Category «nut factor»

Calculating Required Thread Engagement – 1/18/21

Rules-of-thumb for thread engagement typically advise:  For a steel nut member:  1 – 1 ½  times the fastener diameter should be engaged and for aluminum nut members:  2 – 2 ½  times the fastener diameter should be engaged.  But these guidelines frequently result in over-designed joints and sometimes these full-thread lengths just aren’t available in …

What Does the Nut Factor, “K”, Really Encompass?

T = k*Fi*d is the “short form” calculation to determine required installation torque, where T is the target installation torque in in-lbs; Fi is the initial preload; and d is the nominal bolt diameter. Seems like a simple, turn-the-crank calculation at first. The bolt size, d, can be “guesstimated” for an initial design calculation. Initial …