CFS Metric & Imperial Conversion 2

Question 1

A bolt has a shank diameter of 12 mm. What is the closest standard inch fractional size?

Accepted Answer

1/2 inch (12.70 mm)

Answer

12 mm converts to approximately 0.472 inches, and 1/2 inch (0.500 in / 12.70 mm) is the closest standard size.

Question 2

Convert a torque value of 100 N·m to foot-pounds (ft·lbf).

Accepted Answer

73.8 ft·lbf

Answer

1 N·m equals 0.7376 ft·lbf, so 100 N·m × 0.7376 = 73.76 ft·lbf ≈ 73.8 ft·lbf.

Question 3

A fastener specification lists a proof load stress of 120,000 psi. What is this value in MPa?

Accepted Answer

827 MPa

Answer

1 psi = 0.006895 MPa, so 120,000 psi × 0.006895 = 827.4 MPa.

Question 4

An M10 bolt has a pitch of 1.5 mm. What is the approximate threads per inch (TPI) equivalent?

Accepted Answer

16.9 TPI

Answer

TPI = 25.4 ÷ pitch (mm), so 25.4 ÷ 1.5 = 16.93 TPI.

Question 5

Convert 50 inch-pounds (in·lbf) of torque to Newton-meters (N·m).

Accepted Answer

5.65 N·m

Answer

1 in·lbf = 0.1130 N·m, so 50 × 0.1130 = 5.65 N·m.

(CFS) Certified Fastener Specialist Practice Test