Value Comparison of Combination Wrenches

MECH 309 WSU Vancouver

Department of Mechanical Engineering

Team B

Jay LuiTodd May

Cameron MullerTony Nguyen

Mason O’LennickAlex Paradis

Daniel PetersonPatrick Phillips

Trevor PopeJonathan Shaffer

Testing Procedures

Criteria for Comparison:

•Cost

•Microstructure Observations

•Oxidization

•Hardness

•Tolerance

•Bending/Failure

Cost

Combination Wrench Manufacturers Tested:

Manufacturer Price

Pittsburgh $1.25

Master Mechanic $6.00

Husky Pro $8.00

Craftsman $10.00

Snap-on $25.25

Microstructure

Pittsburgh:

Master Mechanic:

Husky Pro:

Craftsman:

Snap-on:

Microstructure

Pittsburgh: Master Mechanic:

Husky Pro: Craftsman: Snap-on:

Pre-Oxidation

Post-Oxidation

Hardness

0.00 10.00 20.00 30.00 40.00 50.00 60.00

43.90

45.08

46.62

48.00

43.52

44.80

41.66

41.96

52.60

53.12

Mean Hardness By Wrench Manufacturer & Treatment

Snap-on, Sample 2

Snap-on

Craftsman, Sample 2

Craftsman

Husky Pro, Sample 2

Husky Pro

Master Mechanic, Sample 2

Master Mechanic

Pittsburgh, Sample 2

Pittsburgh

Hardness (HRC)

Open-End Testing

Torque Applied via Torque Wrench Along Wrench to Maintain Line of Action

Each Wrench Head Plastically Deformed Around Test Bolt Preventing Fracture

The Amount of Play in the Open-End of Each Wrench Correlated to Slippage

Open-End Tolerance

0.00% 5.00% 10.00% 15.00% 20.00% 25.00% 30.00% 35.00% 40.00% 45.00% 50.00%

43.62%

19.92%

11.01%

0.00%

0.00%

Play on Test Bolt By Manufacturer

Snap-on

Craftsman

Husky Pro

Master Mechanic

Pittsburgh

Percentage Difference in Open-End Play

Open-End Failure Results

0.0 10.0 20.0 30.0 40.0 50.0 60.0

40.0

40.4

56.1

56.1

49.1

Open-End Wrench Failure

Snap-on

Craftsman

Husky Pro

Master Mechanic

Pittsburgh

Applied Moment (ft-lb)

t

Handle Failure Results

Pittsburgh

Snap-on

Craftsman

Master Mechanic

Husky

Handle Failure Results

0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0

140.8

162.5

181.8

147.8

171.1

Closed-End Wrench Failure

Snap-on

Craftsman

Husky Pro

Master Mechanic

Pittsburgh

Moment Applied to Handle Resulting in Failure (ft-lb)

Handle Failure Results

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0

28.2

28.7

24.8

23.3

30.2

Mass Value – Ratio of Torque per Mass

Snap-on

Craftsman

Husky Pro

Master Mechanic

Pittsburgh

ft-lb per gram

Conclusions

•Husky• Best value, good toughness and low-cost• Warranty may not be as good as high-cost wrenches

•Snap-on • Performed well but the high cost makes it a lower value• Has excellent warranty and highest failure points

•Craftsman• Best choice if failure is a concern• Good value and lifetime warranty

•Master Mechanic • Performed adequately• But for $2 more, the best value wrench, Husky, could be purchased instead

•Pittsburgh• Low-cost was evident with its low failure points and inconsistency

Questions

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