How to Identify a BoltHow to Identify a Bolt

The parts of a BoltThe parts of a Bolt

A Scale (or Ruler) is used to A Scale (or Ruler) is used to determine the dimensions of a determine the dimensions of a

bolt.bolt.

One Side is Inches and the One Side is Inches and the other is Millimetersother is Millimeters

The 16The 16thth Scale is easier than Scale is easier than the 32the 32ndnd Scale for measuring Scale for measuring

Fractional bolts.Fractional bolts.

Step 1 Step 1

Determine if the bolt is Metric or Standard

Is this metric or standardIs this metric or standard

Is this metric or standard?Is this metric or standard?

Step 2 is to determine the Step 2 is to determine the SizeSize

Size means the diameter of the bolt across the threads.

What is the size of this What is the size of this standard bolt?standard bolt?

What is the size of this metric What is the size of this metric bolt?bolt?

Step 3 is to determine the Step 3 is to determine the thread pitch.thread pitch.

Pitch means the number of threads per inch for a standard bolt.

Pitch means the distance between threads for a metric bolt.

Thread pitch is measured with Thread pitch is measured with a thread pitch gagea thread pitch gage

What is the pitch of this metric What is the pitch of this metric bolt?bolt?

What is the pitch of this What is the pitch of this standard bolt?standard bolt?

Step 4 is to measure the Step 4 is to measure the lengthlength

Length is measured from the bottom of the head to the end of the thread

What is the length of this What is the length of this standard bolt?standard bolt?

What is the length of this What is the length of this metric bolt?metric bolt?

The 5The 5thth step is to determine step is to determine the Head size.the Head size.

Head size is measured from flat to flat.

What is the head size of this What is the head size of this metric bolt?metric bolt?

What is the head size of this What is the head size of this standard bolt?standard bolt?

If the threads are damaged If the threads are damaged what tool is used to repair what tool is used to repair

them?them?

DieDie

Die SizeDie Size

Standard Die Size – PitchExample: 3/8 – 14

Metric Die Size – PitchExample: 10 X 1.25

Head SizeHead Size

Standard Bolt SizingStandard Bolt Sizing

Metric Bolt SizingMetric Bolt Sizing

8.8