Product Selection Criteria (STAMPS)
Bolt Force – Bolt #1 – No Lubricant
The device shown is a bolt tension device that is designed to measure load generated in pounds (lbs) when a given torque value is applied. In this example, a 5/8” SAE Grade 5 coarse thread carbon steel bolt has been installed and torqued to 60 ft. lbs. The resulting stress that is generated is 4200lbs.
Bolt Force – Bolt #2 – Zinc-Plated, No Lubricant
In this example, we are now using the same size and grade, but this is a zinc-plated bolt. As you can see, in this case, the coating improves the efficiency of the bolt and the load generated. When the same torque of 60 ft. lbs. is applied, the compressive force generated increases to 5800lbs.; nearly a 30% increase in available compressive force.
Bolt Force – Bolt #3 – Zinc-plated with Lubricant
The last example is the same size and grade zinc-plated bolt, but with thread lubricant (nickel-based Never Seiz). The compressive load generated with the same initial torque of 60 ft. lbs. is now 8400lbs! That is twice the force generated by the original carbon steel bolt, thus proving the importance of properly lubricating bolts.