# Kyoto2.org

Tricks and tips for everyone

# What is the difference between breakaway torque and running torque?

## What is the difference between breakaway torque and running torque?

Breakaway torque is the turning force required to initiate rotation (similar to static friction), and running torque is the turning force required to keep a system in rotation (similar to kinetic friction).

## Is breakaway torque higher than tightening torque?

Breakaway torque is the rotating force required to “break” the head loose, going in the same direction as applied – tightening. This will usually give a value HIGHER than the original tightening torque because dynamic (when the bolt was tightened) is lower than static (when you try to break loose the bolt head).

How do you measure breakaway torque?

To conduct this test, take a screw or bolt that is tightened down and begin to loosen it. When the fastener breaks loose, record the torque reading. The torque value to loosen the fastener is the approximate torque that was applied to the joint.

How do you measure running torque?

The proper procedure is to run the nut or bolt down to maybe half a turn to contact (washer still loose). Measure the torque required just to move the nut the last bit before the nut makes contact, and add that to the total.

### Why is breakaway torque less than tightening torque?

The torque needed to stretch the fastener always acts in the untightening direction and it’s for this reason that the untightening torque is less than the tightening torque.

### What is the purpose of running torque?

Running torque refers to the amount of torque a device needs to maintain the constant angular velocity of a rotating part once in operation. Knowing this value provides important operating information for rotation machinery and requires testing to determine it.

What is breakout torque?

Breakout torque is the force required to loosen a securely tightenedâ€”and corrodedâ€”nut or bolt. If threads are sufficiently corroded, that torque might be two or three times the tightening torque.

What is the running torque?

Running torque is the determination of how much torque is required to keep the part rotating at a constant angular velocity once it starts rotating.

#### What is breakaway torque of motor?

Breakaway torque is defined as how much torque is required to start a part’s rotation from a stationary position. Running torque is the determination of how much torque is required to keep the part rotating at a constant angular velocity once it starts rotating.

#### What is breakaway torque affected by?

Breakaway torque occurs when an already installed screw is further rotated or loosened. The preload force results from the tightening of the screw. The torque is applied while the screw is rotated until it is tight. The torque which starts after the breakaway torque is referred to as prevail torque.

What is Max breakaway torque?

Breakaway torque is the maximum initial force applied when busting a fastener loose.

What is above running torque?

Breakaway torque refers to what a motor needs to start moving a stationary load. Generally, its value is higher than the running torque, which keeps the load rotating at operational speed.