# How is bolt torque determined?

How is bolt torque determined? 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 is installation torque calculated? 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.)

How do you measure torque on a bolt without a torque wrench?

Does length of bolt affect torque? Tightening torque is not influenced by the bolt length so easy to standardize. The Bolt efficiency will be low due to wide tolerance of the tension.

## How is bolt torque determined? – Additional Questions

### How much torque does a 1/2 inch bolt have?

US Recommended Bolt Torque
Size Recommended Torque
1/2″ 37 45
9/16″ 53 63
5/8″ 73 104

### What does K mean in torque?

A “short form” equation for converting between torque and tension has been developed: T = K×F×D. where T is the torque measurement, K is the nut factor, F is the tension and D is the bolt diameter.

### Do you torque the nut or the bolt?

In simple terms, you need torque to create tension in a bolt. You use torque to turn a nut onto a bolt and then to stretch the bolt, making it a solid spring that clamps the two materials together.

### Does bolt length matter?

Does length really matter? The length of a bolt and the number of threads has a bearing on proper tension. Most stretching occurs in the threaded portion of the bolt. Automotive engineers size bolts, to provide adequate stretch and substituting a different length can cause problems.

### Does bolt length affect strength?

Conclusion. This study showed that increasing the bolt length for the same tightening torque tends to increase the fatigue strength of the joint.

### Are longer bolts weaker?

A longer bolt will be more dependable in applications that are subject to vibration and other cyclic loads. Because it retains a higher percentage of the all-important clamping force, the longer bolt provides more stability and reliability.

### Can bolts be too long?

If the wheel bolts are too long, they can’t properly fasten the wheels. Getting the wheel fastener length right is critical with regard to safe wheel installation. Sadly, people often overlook them, after all, they are small components. However, they play a significant role in keeping you safe while driving.

### How many threads should be left on a bolt?

How many threads should protrude through a nut in an optimal joint? The generally accepted answer is 1 to 3 threads. Most externally threaded fastener blanks are manufactured with a header point prior to thread rolling, which leaves the first 1 to 2 threads undersized for ease of assembly.

### How far should a bolt go through a nut?

The depth of a fastener should be at least two times its nominal diameter. For example a 1/4in (0.25in) fastener should be threaded at least 1/2in (0.50in) deep.

### How far should a bolt protrude through a nut?

Threaded fasteners, when installed and tightened, should protrude a distance of at least one thread beyond the top of the nut or plastic insert. Excessive protrusion should be avoided, particularly when necessary clearances, accessibility, and safety are important.

### How many threads do you need for full strength?

It is commonly known that the minimum recommended thread engagement to make a strong connection for a component with a tapped hole is approximately 1 times the nominal diameter in steel and 2 times the nominal diameter in aluminum.