JPL Bolt Torque

JPL Spec ES504255 I

General Specification

CODE IDENT NO. 23835SPEC NO. ES504255, REV IISSUE DATE 2/9/99SUPERSEDING ES504255 HDATED 6 JANUARY 1999

TORQUE REQUIREMENTSMECHANICAL THREADED FASTENERS

(SPACECRAFT STRUCTURE EQUIPMENT)GENERAL SPECIFICATION FOR

* Printed copies of this document may not be current and should not be used for officialpurposes. The current version is in the DMIE Information System at http://dmie

Jet Propulsion LaboratoryCalifornia Institute of Technology

JPL Spec ES504255 I

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TABLE OF CONTENTS

Section Page

1. SCOPE................................................................................................................................3

1.1 Contents...............................................................................................................................31.2 Purpose................................................................................................................................31.3 Nonstandard Torques ..........................................................................................................3

2. APPLICABLE DOCUMENTS ........................................................................................3

2.1 Listing..................................................................................................................................3

3. REQUIREMENTS ............................................................................................................6

3.1 Conflicting Requirements....................................................................................................63.2 Installation Holes ................................................................................................................63.2.1 Hole Preparation ................................................................................................................63.2.1.1 Diameters. ...........................................................................................................................63.2.1.2 Perpendicularity..................................................................................................................63.2.1.3 Finish...................................................................................................................................63.2.1.4 Circularity ...........................................................................................................................63.2.1.5 Cleaning ..............................................................................................................................63.3 Fastener Threads ................................................................................................................63.3.1 Unified National Thread .....................................................................................................63.3.2 J Form Thread.....................................................................................................................63.3.3 Preferred Threads ...............................................................................................................63.3.4 Bolt Stress Area...................................................................................................................63.3.5 Bolts, Screws and Nuts ........................................................................................................63.3.6 Preferred Parts....................................................................................................................63.4 Installation ..........................................................................................................................63.4.1 Quantity of Fasteners Used.................................................................................................63.4.2 Wrenches .............................................................................................................................73.4.3 Torque Application..............................................................................................................73.4.3.1 Installation Torque..............................................................................................................73.4.3.2 Standard Torque Values......................................................................................................73.4.3.2.1 Self-Locking Fasteners........................................................................................................73.4.4 Thread Engagement ............................................................................................................73.4.5 Washer Identification ..........................................................................................................73.4.6 Self-Locking Features .........................................................................................................73.4.6.1 Replacement Criteria ..........................................................................................................73.4.7 Thread Length .....................................................................................................................73.4.8 Bolt and Screw Length ........................................................................................................83.4.8.1 Grip Adjustment ..................................................................................................................83.4.9 Washers ...............................................................................................................................83.4.9.1 Washers with Flush Head Fasteners...................................................................................83.4.10 Design Torque Requirements ..............................................................................................83.4.11 Preloads ..............................................................................................................................83.4.11.1 Fasteners assembly .............................................................................................................83.4.11.2 Tapped Holes.......................................................................................................................83.4.11.3 Preloads for Bolts/Screws Installed Into Inserts ................................................................8

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3.4.11.4 Special Preloads.................................................................................................................83.4.11.5 Special Torque Values.........................................................................................................83.4.11.6 Electronic Equipment and Assembly...................................................................................93.4.11.7 Nylon Screws and Nuts........................................................................................................93.5 Torque .................................................................................................................................93.5.1 Installation Torque..............................................................................................................93.5.1.1 Torque Coefficient K ...........................................................................................................93.5.2 Torque Wrench Personnel...................................................................................................93.5.3 Overtorqued Fasteners........................................................................................................93.5.3.1 Retorquing ...........................................................................................................................93.5.4 Multiple Installations .........................................................................................................93.5.5 Lubrication ..........................................................................................................................93.5.6 Torque Tables......................................................................................................................93.5.6.1 Self-Locking Fasteners......................................................................................................10

4. QUALITY ASSURANCE ...............................................................................................10

4.1 Torque Inspection..............................................................................................................104.2 Thread Length Inspection .................................................................................................104.3 Tooling ..............................................................................................................................104.3.1 Torque Wrenches...............................................................................................................104.3.1.1 Tool Accuracy ...................................................................................................................104.3.1.2 Tool Selection....................................................................................................................104.3.1.3 Calibration ........................................................................................................................104.3.1.4 Sealing and Marketing ......................................................................................................104.3.1.5 Recalibration.....................................................................................................................104.3.1.6 Adapters ............................................................................................................................10

5. PREPARATION FOR DELIVERY ..............................................................................10

6. NOTES .............................................................................................................................10

6.1 Intended Use......................................................................................................................106.2 Formulas Used ..................................................................................................................116.3 Definitions .........................................................................................................................126.3.1 Maximum Locking Torque ................................................................................................126.3.2 Breakaway Torque ............................................................................................................12

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TABLE OF CONTENTS (cont'd)

Table Page

I. Rivnuts ...............................................................................................................................13II. Inserts, Bolts/Screws, and Nuts at 80 ksi ..........................................................................13III. Blind Nuts and Anchor Nuts at 125 ksi .............................................................................14IV. Bolts/Screws, at 160 ksi, Into Inserts Assembled in

6061-T6 Aluminum ............................................................................................................15V. Bolts/Screws, at 190 ksi, Installed Into Inserts

Assembled in 6061-T6 Aluminum Alloy. ...........................................................................16VI. Bolts/Screws, at 160 ksi, Into Invar and

Higher Shear Strength Aluminum Alloy............................................................................17VII. Bolts/Screws, at 190 ksi, Into Invar and

Higher Shear Strength Aluminum Alloy............................................................................18VIII. Bolts/Screws, at 160 ksi, assembled in Tapped Material..................................................19IX. Bolts/Screws, at 190 ksi, assembled in Tapped Material..................................................20X. Maximum Prevailing and Minimum Breakaway Torque ..................................................21XI. Nylon Fasteners Assembly Torque....................................................................................21XII. Thread Engagement and Protrusion .................................................................................21

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1. SCOPE

1.1 Contents. This engineering specification defines the standard torque to be applied tothreaded fasteners during spacecraft assembly.

1.2 Purpose. The amount of torque applied establishes the preload in the fastener and the jointclamp-up. Incorrect preload may result in:

a. Static failure of the fastener.

b. Static failure of a joint member.

c. Fatigue failure of the fastener.

d. Joint Separation.

e. Joint Slip.

1.3 Nonstandard Torques. Nonstandard torque values not covered in this specification shall becalled out on the controlling drawing, with any applicable procedures to be applied, as a drawing note.

2. APPLICABLE DOCUMENTS

2.1 Listing. The following documents, of the issue as specified in the contractual instrument (oras specified for use within JPL), form a part of this specification to the extent specified herein:

SPECIFICATIONS

JPL

ES516101 Torque Requirements, Threaded Fasteners, ElectronicPackaging Equipment, General Specification for

Federal

GGG-W-686 Wrench, Torque

Military

MIL-S-7742 Screw Threads, National and Unified National, Preferred Sizes

MIL-S-8879 Screw Threads, Controlled Radius Root with Increased MinorDiameter, General Specification for

MIL-DTL-18240 Fastener Element, Self-Locking, Threaded Fastener, 250? F Max.

MIL-DTL-25027 Nut, Self-Locking, 250 Deg F, 450 Deg F, and 800 Deg F

NASC

NAS618 Fastener-Recommended Shank, Hole and Head-to-Shank FilletRadius for

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STANDARDS

JPL

DS83 Screw, Internal Wrenching, 160 ksi and 190 ksi

DS132 Screw, Pan Head, Hi-Torque Recess, Full Thread, 160ksi CRES

DS134 Screw, Countersunk Head, Hi-Torque Recess, Full Thread, 160 ksi and 190 ksi, CRES

DS136 Bolt, Close Tolerance 12-Point External Wrench, 160 ksi and 190 ksi, CRES

QAI85-15-6-001 Calibration Torque Devices

ST10051 Screw, Cap, Socket Head Hexagon, 80 ksi, CRES

ST10060 Nut, Hexagon, Self-Locking, CRES

ST10072 Screw, Pan Head, Cross Recess, 80 ksi, CRES

ST10073 Screw, Pan Head, Hi-Torque Recess, 160 ksi, CRES

ST10224 Rivnut, Blind, Flat Head, Closed End, Keyed, Aluminum Alloy

ST10225 Rivnut, Blind, Countersunk Head, Closed End, Keyed,Aluminum Alloy

ST11326 Insert, Non-Locking, Threaded, Miniature, Open End

ST11294 Rivnut, Blind, Flat Head, Open End, Keyed, Aluminum Alloy 90273 Washer, Countersunk, CRES

Federal

FED-STD-H28 Screw Thread Standards for Federal Services

Military

MS21076 Nut, Self-Locking, Plate, Two Lug Floating, UNC andUNF2A CRES

MS24693 Screw, Machine, Flat Countersunk Head, Gross Recess

MS35649 Nut, Plain, Hexagon, Machine, UNC-2B, CRES

MS35650 Nut, Plain, Hexagon, Machine, UNF-2B, CRES

MS35691 Nut, Plain, Hexagon, UNF-2B, CRES

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MS51957 Screw, Machine, Panhead, Cross Recess, UNC-2A, CRES

MS51958 Screw, Machine, Panhead, Cross Recess, UNF-2A, CRES

NASC

NAS1216 Screw, Pan Head Slotted Dovetail Recess, Full Threaded Self-Locking Optional

NAS1351 Screw, Cap, Socket Head Undrilled and Drilled, Plain and Self-Locking Alloy Steel, Corrosion-Resistant Steel and Heat-Resistant Steel, UNRF-3A

NAS1352 Screw, Cap, Socket Head Undrilled and Drilled, Plain and Self-Locking Alloy Steel, Corrosion-Resistant Steel and Heat-Resistant Steel, UNRC-3A and UNRC-2A

NAS1348 Fasteners - Recommended Tensile Stress Areas for External Threaded

NAS1394 Insert, Threaded, Metal, Lightweight, CRES

NAS1395 Insert, Threaded, Metal, Heavy Duty, CRES

NAS1580C Bolt, Countersunk Head, CRES

Commercial

Hi-Shear Corp. (CAGE 73197)

BB414 Blind Nut Assembly, Blind Expander

BB415 Blind Nut Assembly, Expander

Rexnord, Inc. (CAGE 29372)

KNB( )J Insert, Non-Locking, Lightweight, Blind

KNCB( )J Insert, Non-Locking, Miniature, Blind

KNC( )J Insert, Non-Locking, Miniature

KNHB( )J Insert, Non-Locking, Heavy Duty, Blind

Shur-Lok Corp. (CAGE 97393)

SL6061C Insert, Blind, Threaded Molded-in, CRES

SL6096C Insert, Threaded, Molded-in, CRES

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(Copies of specifications, standards, procedures, drawings, and publications requiredby suppliers in connection with specific procurement functions should be obtained from the procuringactivity or as directed by such activity.)

3. REQUIREMENTS

3.1 Conflicting Requirements. Conflicts arising between the requirements of this specificationand the requirements of any document referenced herein shall be referred to the procurement activity, ifany, or if not, to the cognizant engineer of the Mechanical Engineering Section (352) for resolution.

3.2 Installation Holes.

3.2.1 Hole Preparation.

3.2.1.1 Diameters. Where possible, hole diameters and tolerances shall conform to NAS618.

3.2.1.2 Perpendicularity. Holes shall be drilled perpendicular to the surface within ±0.5 degree.

3.2.1.3 Finish. Holes shall be smooth and free from any drill chatter or scoring marks.

3.2.1.4 Circularity (Roundness). Holes shall be round within the best shop practice. Holes may bereamed for shear and critical applications.

3.2.1.5 Cleaning. After the holes are machined, they shall be cleaned to remove all contaminantsbefore the bolts are installed.

3.3 Fastener Threads. There will be two different fastener thread series referenced in thisdocument.

3.3.1 Unified National Thread. The Unified National inch thread conforms to FED-STD-H28 andMIL-S-7742.

3.3.2 J Form Thread. The J form thread has the MIL-S-8879 thread form.

3.3.3 Preferred Threads. The J form threads are preferred. The J form external thread shall notbe used with internal Unified National form, MIL-S-7742, without the specific approval of the cognizantengineer.

3.3.4 Bolt Stress Area. Bolt root areas are used to calculate the preloads listed herein. (See 6.2a)

3.3.5 Bolts, Screws and Nuts. The bolt, screw or nut shall not be reworked in any manner; thisincludes drilling, filing, cutting, using a tap or die, or any other mutilation, unless approved by thecognizant engineer, reidentified and inspected by QA.

3.3.6 Preferred Parts. The listing of a part in the Torque Tables does not imply the part isapproved for general use. See Section 352 Fastener Specialist for approvals.

3.4 Installation.

3.4.1 Quantity of Fasteners Used. Only as many fasteners as are anticipated to be installed and

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tightened during a work shift shall be taken from protective stores. Fasteners not used shall be returnedto protective storage containers at the end of the shift.

3.4.2 Wrenches. Sockets and wrenches shall not have sharp edges or burrs that could damage thefastener plating or coating.

3.4.3 Torque Application. Torque shall be applied to the nut to the maximum extent possiblewhen a nut is present. Whenever clearance is a problem, torque may be applied to the bolt head, to thehigh side of the torque range specified in the torque tables.

3.4.3.1 Installation Torque. The torque applied at final assembly shall include the net effect of thefollowing:

a. The torque required to overcome kinetic friction between mating bearing faces andbetween mating threads, plus;

b. The torque required to overcome the self-locking feature (if any), plus;

c. The torque required to apply the desired axial load to a fastener assembly.

The installation torque shall be measured only in the tightening direction.

3.4.3.2 Standard Torque Values. The torque values selected from Tables I through IX are based onthe maximum preload capability of the weaker member of the joint (either the internally threaded orexternally threaded part).

3.4.3.2.1 Self-Locking Fasteners. The self-locking and breakaway torque of fasteners shall bemeasured as specified in 6.3. The self-locking torque shall be added to the value listed in the applicabletable and the fastener installed to that torque value.

3.4.4 Thread Engagement. The nut, nutplate, insert, etc., shall not engage any incomplete threadsadjacent to the bolt or screw shank.

3.4.5 Washer Identification. Any identification mark on the washer used under the nut shall beplaced opposite the face of the nut.

3.4.6 Self-Locking Features. Threaded fasteners should contain a self-locking feature in eitherthe external, or internally threaded part to prevent joint loosening. Self-locking bolts and screws shall bereadily identifiable by marking or discrete part number.

3.4.6.1 Replacement Criteria. The locking elements of self-locking screws and nuts are graduallydegraded with use (an average life of 5 to 10 installations). The prevailing (or running) torque of eachscrew shall be measured during installation, prior to type approval (TA) and flight acceptance (FA)testing and final assembly. The minimum breakaway torque requirements for certain fastenercombinations are listed in Table X. When a screw or nut fails to develop the minimum breakawaytorque, replace it with a new screw or nut.

3.4.7 Thread Length. Install fastener threads to extend through nuts, or nutplates to comply withthe thread minimum protrusion requirements shown in Table XII. Depth of fastener threads into tappedholes or free running inserts shall be one diameter minimum. Depth of fastener threads into lockinginserts shall be as above or a minimum of 1.5 threads through the locking element, whichever is greater.

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3.4.8 Bolt and Screw Length. A bolt or screw one size longer or shorter than that specified on theengineering drawing may be substituted providing:

a. They are only replaced by flight certified fasteners from flight store.

b. They are stock items, controlled or special order bolts and screws readily available innext length sizes.

3.4.8.1 Grip Adjustment. When a longer bolt or screw is substituted, additional washers may beadded to the ones specified on the engineering drawing subject to the following limitations:

a. The number of washers used on a fastener shall be limited to three: one washer underthe head and two under the nut, or two under the head and one under the nut.

b. Countersunk washers shall be installed under bolt heads with the countersunk sidefacing the bolt head.

3.4.9 Washers. Washers shall be used in accordance with the engineering drawing, applicableprocess bulletins and design standards, to reduce or eliminate threads in bearing, or to prevent dissimilarmetal contact. Normally, washers shall be placed under the part of the fastener that is to be wrenched(turned) to prevent galling of the substructure. Countersunk washers (90273 or equivalent) shall be usedto provide sufficient clearance for the fillet radius under the head.

3.4.9.1 Washers with Flush Head Fasteners. Washers shall not be used under flush heads unlessspecified on the engineering drawing.

3.4.10 Design Torque Requirements. Design may specify torque values not listed in the Tablesherein when the design requirements dictate.

3.4.11 Preloads. Preloads shall be as specified in Tables I through IX, as applicable.

3.4.11.1 Fastener Assembly. Fastener assembly preload shall be based on 50 percent of the fastenertensile strength (see 6.2b).

3.4.11.2 Tapped Holes. Preloads for bolts/screws assembled into tapped holes shall be limited by theparent materials shear yield strength (Fsy) (see 6.2c).

3.4.11.3 Preloads for Bolts/Screws Installed Into Inserts. Preloads for bolts/screws installed intoinserts that are assembled in various materials shall be based on the applicable Fsy of the parent material(see 6.2d).

3.4.11.4 Special Preloads. For critical preloaded structural assembly tension and shear applications,torque values based on higher percentages of tensile yield strength shall be permitted with the approvalof the cognizant engineer and the Structures and Materials Review Committee. The special torque valuesshall be specified on the engineering drawing.

3.4.11.5 Special Torque Values. Preload torque may be determined by analysis as the torque valuerequired to ensure joint assembly integrity, considering all loading, thermal, and operationalenvironments and applicable safety factors, where torque-tension testing is not justifiable, or where dataexists with similar design configuration which support the analysis.

3.4.11.6 Electronic Equipment and Assembly. Torque values for electric and electronic packaging

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equipment shall be in accordance with ES516101.

3.4.11.7 Nylon Screws and Nuts. Torque values for nylon screws and nuts shall be as specified inTable XI.

3.5 Torque.

3.5.1 Installation Torque. Installation torque shall be in inch-ounces, inch-pounds, or foot-pounds(see 6.2e).

3.5.1.1 Torque Coefficient K. The torque coefficient (K) shall be determined by torque-tensiontests or may be estimated as follows:

0.25 - No lubrication on nut or bolt

0.21 - Lubricated threads or lubricated head/washer only and silver plated nuts onto bareA-286 bolts when torques applied to the head.

0.15 - Silver plated nuts with unlubricated A-286 bolts, torque applied to the nut.Bolts/screws with dry film lubricated threads and head/washer, torque applied tothe head, going into unlubricated inserts and tapped holes.

3.5.2 Torque Wrench Personnel. All tightening of fasteners shall be accomplished byexperienced personnel using certified equipment.

3.5.3 Overtorqued Fasteners. Bolts, screws, inserts, and nuts which are tightened to torqueswhich exceed values specified shall be removed and replaced with new fasteners.

3.5.3.1 Retorquing. The effect of retorquing on a fastener torque-load relationship can besignificant. All activities which install fasteners should consider the potential effects on preload thatretorquing fasteners can have on installed hardware.

3.5.4 Multiple Installations. On multiple bolt, screw, or nut installations (e.g., circular boltedjoints, etc.) the following procedure for torquing shall apply:

a. Finger tighten all fasteners.

b. Snug up diagonally opposite fasteners until all fastener heads are seated.

c. Torque to within proper limits in a criss-cross pattern; do not successively tightenfasteners that are next to each other.

3.5.5 Lubrication. Fasteners shall be installed in the received condition without additionallubrication.

3.5.6 Torque Tables. Torque Tables I through VII shall be used to determine the torque for thespecific combinations of inserts, nuts, bolts or screws, and washers listed therein. Torque Tables VIIIand IX shall be used to determine the installation torque required for installation of bolts/screws intapped holes.

3.5.6.1 Self-Locking Fasteners. When self-locking fasteners are used, the torque required toovercome the locking feature's torque (running torque) shall be added to the torque value indicated in the

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Table.

4.0 QUALITY ASSURANCE

4.1 Torque Inspection. All threaded fasteners torqued to the requirements of this specificationshall be 100 percent inspected for proper torque during assembly.

4.2 Thread Length Inspection. Fastener thread length shall be inspected for conformance to therequirements of 3.4.7.

4.3 Tooling.

4.3.1 Torque Wrenches. Torque shall be applied to the fasteners using torque wrenchesconforming to QAI 85-15-6-001 and GGG-W-686.

4.3.1.1 Tool Accuracy. Wrenches shall be capable of indicating torque within ±4 percent. Newtools may require two applications before the accuracy is within the ±4 percent requirements.

4.3.1.2 Tool Selection. The torque wrench to be used shall be chosen such that the specified torquevalues for a particular fastener shall be between 20 and 80 percent of the full-scale torque.

4.3.1.3 Calibration. Torque wrench calibration shall be checked prior to the first use and thereafterat intervals not to exceed 30 calendar days. The interval may also be adjusted by individual gageinspection card. A dated certification of such check shall be securely attached to the wrench.

4.3.1.4 Sealing and Marking. Torque presetting wrenches shall be sealed after adjustment andcalibration check with a suitable tamperproof material. The torque to which the wrench is set shall beclearly and conspicuously marked on the wrench.

4.3.1.5 Recalibration. If a torque wrench is dropped, struck or otherwise damaged, or suspected ofbeing out of calibration, the wrench shall be checked before further use and, if found to be out ofcalibration, the wrench shall not be used until recalibrated.

4.3.1.6 Adapters. Adapters or extensions shall be used with torque wrenches only when necessary.Adapters or extensions shall be used only with wrenches designed for their use and the wrench or adaptercombination shall be calibrated prior to use, or correction made for actual torque by an acceptableanalytical method.

5.0 PREPARATION FOR DELIVERY

Not applicable.

6.0 NOTES

6.1 Intended Use. Torque values are to be used in the assembly of spacecraft structure, subassemblies, and other areas as indicated.

6.2 Formulas Used:

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a. Bolt/Screw Tensile Strength (F0)

F0 = As x Ftu

F0 = Tensile Strength (lbs) As = Root Area From FED-STD-H28 (in²) Ftu = Tensile Strength (psi)

b. Preload (F) Fastener Assembly

F = 0.5 x Ftu x As

F = Fastener preload (lbs) As = Root Area (in²)

c. Preload (F) for Fastener Assembly Into Tapped Hole

F = 3 x 1n

x 78

x Fsy x d x π

F = Preload (lbs) n = Fasteners Threads per inch (in-1) Fsy = Tapped Material Shear Yield Strength (psi) d = Thread Major Diameter (in)

d. Preload (F), fastener assembled into insert that has been installed in a tapped hole.

F = Ase x

1L

x 3n

x Fsy

F = Preload (lbs) L = External Thread Length of Insert (in) n = Threads per inch, External Insert Threads (in-1) Ase= Shear Engagement Area(*) of External Insert Threads (in2) Fsy = Shear Yield Strength of Parent Material (psi) (*) Supplied by manufacturer of insert.

e. Torque (T) Necessary to Achieve Specified Preload.

T = KFd (0.95)

T = Assembly Torque (in-lbs) K = Constant:Required Loading Factor, Non-dimensional F = Preload (lbs) d = Major Diameter of External Thread (in) 0.95 = Allowance for Torque Wrench Error.

6.3 Definitions. For the purpose of clarification and interpretation, the following definitions areapplicable to this specification.

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6.3.1 Maximum Locking Torque. The maximum torque is measured during the installation orremoval cycle with no load on the base of the nut. On the first installation cycle, maximum lockingtorque is defined as the highest reading measured during the turn of the nut after the top of the nut isflush with the end of the bolt.

6.3.2 Breakaway Torque. After assembly, the nut shall be backed-off (counterclockwise) until thepreload on the assembly is removed and then the turning shall be stopped. The breakaway torque is thetorque required to start the nut turning again in a counterclockwise direction.

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Table I. Rivnuts

Rivnut Numbers: ST10224, ST10225

Mating Bolts/Screws: Any with 25ksi or greater tensile strength.

Torque Wrench Reading (Inch-Ounces)K=0.15 K=0.21 K=0.25

PreferredThread Size

PreloadPounds

Max Min Max Min Max Min0.112-40 58 14.8 12.0 20.7 16.8 24.7 20.00.138-32 87 27.4 22.2 38.3 31.0 45.6 37.00.164-32 141 52.7 42.7 73.8 59.8 87.9 71.20.190-32 209 90.5 73.3 127 103 151 122

Table II. Inserts, Bolts/Screws and Nuts at 80ksi

Part Numbers Inserts: SL6061C, SL6096C Bolts/Screws: MS24693[1], MS51957, MS51958 ST10051, ST10072, NAS1352C, NAS1351C Nuts: MS35649, MS35650, MS35691 [2]

Mating Bolt/Screw: Any with 80ksi or greater tensile strength.

Torque Wrench Reading(Inch-Ounces)K=0.15 K=0.21 K=0.25


PreloadPounds

Max Min Max Min Max Min0.060-80 58 7.9 6.5 11.1 9.0 13.2 10.70.086-56 120 23.5 19.1 32.9 26.7 39.2 31.80.112-40 192 49.0 39.7 68.6 55.6 81.7 66.2

Torque Wrench Reading(Inch-Pounds)K=0.15 K=0.21 K=0.25


PreloadPounds

Max Min Max Min Max Min0.138-32 288 5.7 4.6 7.9 6.4 9.4 7.60.164-32 473 11.1 9.0 15.5 12.6 18.4 14.90.190-32 700 18.9 15.3 26.5 21.5 31.6 26.60.250-28 1300 46.3 37.5 64.8 52.5 77.2 62.5

Notes:

[1] Use 80 percent of the listed torque for MS24693 and other flush head screws.

[2] MS35691 is a jam nut, use 50 percent of the listed torque.

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Table III. Blind Nuts and Anchor Nuts at 125ksi.

Part Numbers: Blind Nuts: BB414, BB415 Anchor Nuts: MS21076

Mating Bolts/Screws: Any with 125ksi or greater tensile StrengthTorque Wrench Reading(Inch-Pounds)K=0.15 K=0.21 K=0.25


PreloadPounds

Max Min Max Min Max Min0.138-32 435 8.6 6.9 12.0 9.7 14.3 11.50.164-32 707 16.5 13.4 23.1 18.7 27.5 22.30.190-32 1040 28.2 22.8 39.4 31.9 46.9 38.00.250-28 1950 69.5 56.3 97.3 78.8 116 93.8

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Table IV. Bolts/Screws at 160ksi, into Inserts Assembled in Al 6061-T6 and Higher Strength Materials.

Bolts/Screws: DS83A-()-(), DS132-()-(), DS134A-()-()[1], DS136A-()-(),NAS1580C()H[1], NAS1216E(), NAS1351N(),NAS1352N(), ST10073-().

Parent Material: Al 6061-T6 and all other materials having higher than Fsy=22.5ksi

Miniature InsertsTorque Wrench Reading(Inch-Pounds)K=0.15 K=0.21 K=0.25


Closed InsertNumber

Open InsertNumber

PreloadPounds

Max Min Max Min Max Min0.060-80 KNC0080J 120 1.0 0.8 1.4 1.2 1.7 1.40.086-56 ST11326-1 233 2.9 2.3 4.0 3.2 4.8 3.90.112-40 ST11326-2 371 5.9 4.8 8.3 6.7 9.9 8.00.138-32 ST11326-3 557 11.0 8.9 15.3 12.4 18.3 14.80.164-32 ST11326-4 905 21.1 17.1 29.6 24.0 35.2 28.6

Lightweight InsertsTorque Wrench Reading(Inch-Pounds)

K=0.15(2) K=0.21 K=0.25Preferred

Thread SizeClosed Insert

NumberOpen Insert

NumberPreloadPounds

Max Min Max Min Max Min0.086-56 KNCB0256J 233 2.9 2.3 4.0 3.2 4.8 3.90.112-40 KNCB0440J 371 5.9 4.8 8.3 6.7 9.9 8.00.138-32 KNCB0632J 557 11.0 8.9 15.3 12.4 18.3 14.80.164-32 KNCB0832J 905 21.1 17.1 29.6 24.0 35.2 28.60.190-32 KNB1032J NAS1394C3 1340 36.3 29.4 50.8 41.1 60.5 49.00.250-28 KNB428J NAS1394C4 2500 89.1 72.1 125 101 148 120

Heavy Duty InsertsTorque Wrench Reading(Inch-Pounds)

K=0.15(2) K=0.21 K=0.25Preferred


NumberOpen Insert

NumberPreload Pounds

Max Min Max Min Max Min0.164-32 KNHB0832J NAS1395C08 905 21.1 17.1 29.6 24.0 35.2 28.60.190-32 KNHB1032J NAS1395C3 1340 36.3 29.4 50.8 41.1 60.5 49.00.250-28 KNHB428J NAS1395C4 2500 89.1 72.1 125 101 148 120

Note [1]. Use 80 percent of the indicated torque values for DS134A-()-() and NAS1580C()H countersunk head parts.

[2]. For 0.190-32 fasteners and larger use the low end of the torque range .

JPL Spec ES504255 I

16

Table V. Bolts/Screws at 190ksi, into Inserts Assembled in Al 6061-T6 and Higher Strength Materials.

Bolts/Screws: DS83-()-(), DS134-()-()[1], DS136-()-()

Parent Material: Al 6061-T6 and all other materials having higher than Fsy=22.5ksi



Closed InsertNumber

Open InsertNumber

PreloadPounds



K=0.15(2) K=0.21 K=0.25Preferred


NumberOpen Insert

NumberPreloadPounds



K=0.15(2) K=0.21 K=0.25Preferred


NumberOpen Insert


Max Min Max Min Max Min0.164-32 KNHB0832J NAS1395C08 1080 25.2 20.4 35.3 28.6 42.1 34.10.190-32 KNHB1032J NAS1395C3 1625 44.0 35.6 61.6 49.9 73.3 59.40.250-28 KNHB428J NAS1395C4 2970 106 85.7 148 120 176 143

Note [1]. Use 80 percent of the indicated torque values for DS134-()-() countersunk head parts.

[2]. For 0.190-32 fasteners and larger use the low end of the torque range.

JPL Spec ES504255 I

17

Table VI. Bolts/Screws at 160ksi, into Inserts Assembled in Invar and Higher Strength Aluminum Alloys.

Bolts/Screws: DS83A-()-(), DS132-()-(), DS134A-()-()[1], DS136A-()-(),NAS1580C()H[1], NAS1216E(), NAS1351N(),NAS1352N(), ST10073-().

Parent Material: Invar and other materials having higher than Fsy=24ksi



Closed InsertNumber

Open InsertNumber

PreloadPounds

Max Min Max Min Max Min0.060-80 KNC0080J 120 1.0 .8 1.4 1.2 1.7 1.40.086-56 ST11326-1 233 2.9 2.3 4.0 3.2 4.8 3.90.112-40 ST11326-2 371 5.9 4.8 8.3 6.7 9.9 8.00.138-32 ST11326-3 557 11.0 8.9 15.3 12.4 18.3 14.80.164-32 ST11326-4 905 21.1 17.1 29.6 24.0 35.2 28.6


K=0.15(2) K=0.21 K=0.25Preferred


NumberOpen Insert

NumberPreloadPounds



K=0.15(2) K=0.21 K=0.25Preferred


NumberOpen Insert


Max Min Max Min Max Min0.164-32 KNHB0832J NAS1395C08 905 21.1 17.1 29.6 24.0 35.2 28.60.190-32 KNHB1032J NAS1395C3 1340 36.3 29.4 50.8 41.1 60.5 49.00.250-28 KNHB428J NAS1395C4 2500 89.1 72.1 125 101 148 120

Note [1]. Use 80 percent of the indicated torque values for DS134A-()-() and NAS1580C()H countersunk head parts.


JPL Spec ES504255 I

18

Table VII. Bolts/Screws at 190ksi, into Inserts Assembled in Invar and Higher Strength Aluminum Alloys.


Parent Material: Invar and other materials having higher than Fsy=24ksi



Closed InsertNumber

Open InsertNumber

PreloadPounds



K=0.15(2) K=0.21 K=0.25Preferred


NumberOpen Insert

NumberPreloadPounds

Max Min Max Min Max Min0.086-56 KNCB0256J 277 3.4 2.8 4.8 3.9 5.7 4.60.112-40 KNCB0440J 441 7.0 5.7 9.9 8.0 11.7 9.50.138-32 KNCB0632J 662 13.0 10.5 18.2 14.8 21.7 17.60.164-32 KNCB0832J 1080 25.2 20.4 35.3 28.6 42.1 34.10.190-32 KNB1032J NAS1394C3 1625 44.0 35.6 61.6 49.9 73.3 59.40.250-28 KNB428J NAS1394C4 2880 103 83.1 144 116 171 139


K=0.15(2) K=0.21 K=0.25Preferred


NumberOpen Insert


Max Min Max Min Max Min0.164-32 KNHB0832J NAS1395C08 1080 25.2 20.4 35.3 28.6 42.1 34.10.190-32 KNHB1032J NAS1395C3 1625 44.0 35.6 61.6 49.9 73.3 59.40.250-28 KNHB428J NAS1395C4 2970 106 85.7 148 120 176 143

Note [1]. Use 80 percent of the indicated torque values for DS134-()-() countersunk head parts.


JPL Spec ES504255 I

19

Table VIII. Bolts/Screws at 160ksi, Assembled into Tapped Material

Bolts/Screws: DS83A-()-(), DS132-()-(), DS134A-()-()[1], DS136A-()-(), NAS1216E(), NAS1351N(), NAS1352N(), NAS1580C()H[1], ST10073-().

Part A. Tapped Al 6061-T6, Fsy=22.5 ksiTorque Wrench Reading(Inch-Pounds)

K=0.15(2) K=0.21 K=0.25Tapped ThreadSize Preload Pounds

Max Min Max Min Max Min0.060-80 120 1.0 .8 1.4 1.2 1.7 1.40.086-56 233 2.9 2.3 4.0 3.2 4.8 3.90.112-40 371 5.9 4.8 8.3 6.7 9.9 8.00.138-32 557 11.0 8.9 15.3 12.4 18.3 14.80.164-32 905 21.1 17.1 29.6 24.0 35.2 28.60.190-32 1100 29.8 24.1 41.7 33.8 49.6 40.20.250-28 1660 59.1 47.9 82.8 67.1 98.6 79.8

Part B. Tapped Invar, Fsy=24 ksiTorque Wrench Reading(Inch-Pounds)

K=0.15(2) K=0.21 K=0.25Tapped Thread

SizePreload Pounds

Max Min Max Min Max Min0.060-80 120 1.0 .8 1.4 1.2 1.7 1.40.086-56 233 2.9 2.3 4.0 3.2 4.8 3.90.112-40 371 5.9 4.8 8.3 6.7 9.9 8.00.138-32 557 11.0 8.9 15.3 12.4 18.3 14.80.164-32 905 21.1 17.1 29.6 24.0 35.2 28.60.190-32 1180 31.9 25.9 44.7 36.2 53.2 43.10.250-28 1770 63.1 51.1 88.3 71.5 105 85.1

Part A. Tapped Al 7075-T73 Fsy=27.5 ksiTorque Wrench Reading(Inch-Pounds)


Max Min Max Min Max Min0.060-80 120 1.0 .8 1.4 1.2 1.7 1.40.086-56 233 2.9 2.3 4.0 3.2 4.8 3.90.112-40 371 5.9 4.8 8.3 6.7 9.9 8.00.138-32 557 11.0 8.9 15.3 12.4 18.3 14.80.164-32 905 21.1 17.1 29.6 24.0 35.2 28.60.190-32 1340 36.3 29.4 50.8 41.1 60.5 49.00.250-28 2025 72.1 58.4 101 81.8 120 97.4

Part A. Tapped Titanium and Steel, Fsy=50.5 ksiTorque Wrench Reading(Inch-Pounds)


Max Min Max Min Max Min0.060-80 120 1.0 .8 1.4 1.2 1.7 1.40.086-56 233 2.9 2.3 4.0 3.2 4.8 3.90.112-40 371 5.9 4.8 8.3 6.7 9.9 8.00.138-32 557 11.0 8.9 15.3 12.4 18.3 14.80.164-32 905 21.1 17.1 29.6 24.0 35.2 28.60.190-32 1340 36.3 29.4 50.8 41.1 60.5 49.00.250-28 2500 89.1 72.1 125 101 148 120

Note [1]. Use 80 percent of the listed torque values for DS134A-()-() and NAS 1580C()H Flush fasteners.

[2] Use the high end of the torque range when applying torque to a nut. Use the low end of the torque range when applying torque to the bolt head and using lubricated threads and a lubricated head/washer and using fasteners 0.190-32 and larger.

JPL Spec ES504255 I

20

Table IX. Bolts/Screws at 190ksi, Assembled into Tapped Material


Part A. Tapped Al 6061-T6, Fsy=22.5 ksiTorque Wrench Reading(Inch-Pounds)


SizePreload Pounds

Max Min Max Min Max Min0.060-80 139 1.2 1.0 1.7 1.4 2.0 1.60.086-56 277 3.4 2.8 4.8 3.9 5.7 4.60.112-40 441 7.0 5.7 9.9 8.0 11.7 9.50.138-32 662 13.0 10.5 18.2 14.8 21.7 17.60.164-32 951 22.2 18.0 31.1 25.2 37.0 30.00.190-32 1100 29.8 24.1 41.7 33.8 49.6 40.20.250-28 1660 59.1 47.9 82.8 67.1 98.6 79.9

Part B. Tapped Invar, Fsy=24 ksiTorque Wrench Reading(Inch-Pounds)


SizePreload Pounds

Max Min Max Min Max Min0.060-80 139 1.2 1.0 1.7 1.4 2.0 1.60.086-56 277 3.4 2.8 4.8 3.9 5.7 4.60.112-40 441 7.0 5.7 9.9 8.0 11.7 9.50.138-32 662 13.0 10.5 18.2 14.8 21.7 17.60.164-32 1010 23.6 19.1 33.0 26.8 39.3 31.90.190-32 1180 31.9 25.9 44.7 36.2 53.2 43.10.250-28 1770 63.1 51.1 88.3 71.5 105 84.1

Part A. Tapped Al 7075-T73 Fsy=27.5 ksiTorque Wrench Reading(Inch-Pounds)


SizePreload Pounds

Max Min Max Min Max Min0.060-80 139 1.2 1.0 1.7 1.4 2.0 1.60.086-56 277 3.4 2.8 4.8 3.9 5.7 4.60.112-40 441 7.0 5.7 9.9 8.0 11.7 9.50.138-32 662 13.0 10.5 18.2 14.8 21.7 17.60.164-32 1080 25.2 20.4 35.3 28.6 42.1 34.10.190-32 1347 36.5 29.5 51.1 41.4 60.8 49.20.250-28 2025 72.1 58.4 101 81.8 120 97.4

Part A. Tapped Titanium and Steel, Fsy=50.5 ksiTorque Wrench Reading(Inch-Pounds)


SizePreload Pounds

Max Min Max Min Max Min0.060-80 139 1.2 1.0 1.7 1.4 2.0 1.60.086-56 277 3.4 2.8 4.8 3.9 5.7 4.60.112-40 441 7.0 5.7 9.9 8.0 11.7 9.50.138-32 662 13.0 10.5 18.2 14.8 21.7 17.60.164-32 1080 25.2 20.4 35.3 28.6 42.1 34.10.190-32 1625 44.0 35.6 61.6 49.9 73.3 59.40.250-28 2970 106 85.7 148 120 176 143

Note [1]. Use 80 percent of the listed torque values for DS134A-()-() and NAS 1580C()H Flush fasteners

[2] Use the high end of the torque range when applying torque to a nut. Use the low end of the torque range when applying torque to the bolt head and using lubricated threads and a lubricated head/washer and using fasteners 0.190-32 and larger.

JPL Spec ES504255 I

21

Table X. Maximum Prevailing and Minimum Breakaway Torque.Prevailing Torque [1]

Maximum (Inch-Pounds)Breakaway Torque

Minimum (Inch-Pounds)Thread Size

Nuts [2] Bolts [3] Nuts [2] Bolts[3]0.086-56 2.5 0.20.112-40 5 5 0.5 0.50.138-32 10 8 1.0 1.00.164-32 15 12 1.5 1.50.190-32 18 18 2.0 2.00.250-28 30 30 3.5 3.0

[1] Prevailing torque on or off. [2] Nut torque values from MIL-DTL-25027 [3] Bolt torque values from MIL-DTL-18240

Table XI. Nylon Fastener Assembly Torque

Nylon Screw/ NutSize

Assembly Torque(Inch-Ounces)

0.112-40 80.138-32 160.164-32 27

Table XII. Thread Engagement and Protrusion.Thread Size Thread Engagement

with Insert MinimumThread Protrusion

Through NutMinimum

0.060-80 0.060 0.0190.086-56 0.086 0.0270.112-40 0.112 0.0380.138-32 0.138 0.0470.164-32 0.164 0.0470.190-32 0.190 0.0470.250-28 0.250 0.054

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JPL Bolt Torque