Initial Torque

Initial torque is the first torque applied to a fastener at the start of tightening, when the threads begin to engage and the head (or nut) first starts to seat against the joint surface. At this stage, most of the torque is overcoming thread friction and under-head (or under-nut) friction, and only a small amount of clamp load may be developed until the joint surfaces are fully seated. In practical terms, “initial torque” is often associated with the early part of the tightening process before the fastener reaches its specified final torque or target preload.

Initial torque matters because the joint can “settle” as surfaces embed and coatings compress, which can change how torque translates into bolt tension. If a fastener is tightened too quickly or with inconsistent seating, the torque reading can be misleading - showing resistance even though clamp load is still low. Many assembly procedures account for this by using a snugging step, a torque-plus-angle method, or a staged tightening pattern to ensure parts seat evenly and the final torque (and resulting preload) is more consistent across the joint.

Learn more about initial torque vs. final torque.