Design & analysis expertise in mobile equipment & bolted joints
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 …
(and how does this affect the nut factor?) The terms “bolt“ and “capscrew” are commonly used interchangeably. But the variations between the two are fairly significant from a manufacturing perspective and assembly standpoints. What’s the difference? Why does it matter? A bolt is designed for insertion through holes in assembled parts to mate with a …
Since bolts and nuts stretch slightly under load, the distribution of stress on the threads is not uniform. Theoretically, the first thread takes a third of the load, the first three threads take three-quarters of the load, and the first six threads take nearly the whole load. The percentage of total load carried by engaged …
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 …