How is fastener torque calculated?

DETERMINING TORQUE The general equation for bolt load based on applied torque is T = KFiDb where K = torque coefficient. K is a function of the coefficients of friction and collar friction in the joint, and these are based on variables such as surface finish, coatings, and so on.

How do you calculate bolt torque?

The widely recognized engineering formula, T= K x D x P (to be explained later in this article), was used to provide the chart’s values, but it must be understood that every bolted joint is unique and the optimum tightening torque should be determined for each application by careful experimentation.

Which torque value is used to determine the tightening of fasteners?

Torque wrenches are the most commonly used measures for this torque. They measure the torque applied to the fastener as the wrench tightens the bolt. In the early 20th century, engineers used analog meters.

How do you calculate clamping force from torque?

The general formula related to torque is T = KDF (1) where T is the torque, K, the nut factor, and D, the screw diameter, and F, the clamping force. T, K, and D, combine to provide the axial clamping force “F” between the two parts being assembled.

What is a prevailing torque?

Prevailing torque is defined as the driving torque required to overcome friction in a threaded fastening application, which produces no clamp load, or bolt stretch.

How do you convert tension to torque?

The Torque/Tension Equation is a method used to estimate the torque/tension relationship in an assembly. T = (K D P)/12 can be used to developt a torque value that will achieve a certain tension or clamp load. T = Torque (ft. -lbs.)

What is the tightening torque?

Torque tightening is the accurate application of torque to a nut so that a bolt can hold its load securely without breaking. When you apply the right amount of torque, the bolt is properly stretched so that it can act as a solid spring to clamp the two materials together.

What torque should I use for screws?

Newton Metres (Nm) on drills: 4 to 15Nm is fine for all of those smaller screw driver tasks around the home. 15 to 35Nm is a great all-rounder to drill and drive medium sizes screws and hole drilling.

What is minimum prevailing torque?

The torque required to run a nut down a thread on certain types of nuts designed to resist vibration loosening. The resistance can be provided by a plastic insert or a noncircular head. A type of lock nut which has a prevailing torque to assist in preventing self loosening.

What is a prevailing nut?

A locknut, also known as a lock nut, locking nut, self-locking nut, prevailing torque nut, stiff nut or elastic stop nut, is a nut that resists loosening under vibrations and torque.

Is tension a torque?

“Torque” is simply a measurement of the twisting force required to spin the nut up along the threads of a bolt, whereas “Tension” is the stretch or elongation of a bolt that provides the clamping force of a joint.