Fastener Torque Chart

Dry torque values assume the fastener threads and bearing surfaces are clean and unlubricated. Lubricated torque values account for oil, wax, or anti-seize on the threads, which reduces friction. Because lubrication lowers friction, you need less torque to reach the same clamp load. Using dry torque on a lubricated bolt can over-stress the fastener.

Clamp load is the tension force a bolt exerts on the joint when tightened. It is the actual force holding the parts together. Torque is just the means to achieve clamp load. A properly torqued bolt creates enough clamp load to resist vibration loosening and maintain joint integrity under load.

SAE Grade 5 bolts are made from medium carbon steel with a minimum tensile strength of 120,000 PSI. Grade 8 bolts use alloy steel with a minimum tensile strength of 150,000 PSI. Grade 8 bolts handle higher torque and clamp loads. Grade 5 works for most general applications, while Grade 8 is used in demanding structural and automotive applications.

Metric class 8.8 is roughly equivalent to SAE Grade 5 in tensile strength (about 120,000 PSI or 830 MPa). Metric class 10.9 is roughly equivalent to SAE Grade 8 (about 150,000 PSI or 1040 MPa). The first number in the metric class indicates 1/100th of the minimum tensile strength in MPa.

Yes. Stainless steel fasteners are prone to galling, where the threads seize and weld together during tightening. Applying anti-seize or a thread lubricant prevents galling and provides more consistent clamp load. When using anti-seize, reduce the torque value by approximately 20-25% from dry values.