Do you need to follow torque specs?

For some areas on the vehicle, not following torque specs isn’t a big deal; however, for certain projects following torque specs are vital. Torque wrenches eliminate the possibility of damaging a mating surface between components and the mounting surface. Torque wrenches ensure a proper seal that is level.

What happens if you don’t torque to spec?

Insufficient torque When you apply exactly the right amount of fastening force, you can rest assured that the bolt will transfer the ‘hits’ as well as the load of the belt to the bulk of the engine, which will absorb them. This, in turn, will lead to incorrect belt tension and, eventually, to belt and/or engine damage.

Why is it important to torque the bolts to a certain value?

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.

How can the correct torque for a bolt be determined?

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.

Is torque wrench necessary for lug nuts?

That’s why most owner’s manuals have a torque specification for lug nuts. If you plan to do any major work on your engine or on some major powertrain components, you absolutely need a torque wrench. Torque force can be measured in units of meter-kilograms (mkg), newton-meters (Nm), and pound-feet (lb-ft).

What is the torque spec for?

When attaching a wheel to a vehicle, torque specifications are the amount of force recommended on the hardware to ensure proper installation. It can damage the wheel, strip the bolts and even cause the brake rotors to warp. Too much torque also can damage brake rotors.

How important is lug nut torque?

When installing the wheels on a vehicle after servicing, it is important to torque the lug nuts properly. Lug nuts that are not tightened correctly can ruin wheels, affect rotor runout and can be deadly if the wheel comes off or studs snap. Over-torqueing the lug nuts does not affect runout immediately.

Why is torque sequence important?

Because the joint surfaces compress, tightening one bolt in the vicinity of another will affect the preload generated by the first bolt tightened. A good tightening sequence ensures that an even preload distribution is achieved in the joint (See Dia. A).

How much torque does a bolt need?

US Recommended Bolt Torque

How are torque values determined?

Begin with the formula T = K x U x D x P, where T is the torque, K is a standard representing 1.33, U is the coefficient of friction, D is the diameter of the fasteners, and P is the necessary preload.

Should torque be applied to the nut or the bolt head?

The answer depends on your application and the condition of the materials being fastened. In many situations you can apply torque to either the nut or the bolt head. Both will result in a tight connection and neither will avoid breakage more often (that occurrence can be avoided through other means).

Do all retaining bolts have the same torque spec?

The individual retaining bolts will more than likely have at least one torque spec, but maybe even multiple or different ones per bolt. Example, a water pump that bolts to a timing cover will have long and short bolts. The long bolts that go into the engine block will have a different torque values then the short ones that thread into the cover.

What is bolt disassembly torque?

For the past 40 years, when the oil and gas industry thought of bolt lubricant, it focused on disassembly — i.e. the breakout torque seen at the bolt head or at the nut of the fastener.

How is torque used to create tension?

Torque is used to create tension. Bolts are used to affix two components so that they can resist tensile (pulling apart) and shearing (sliding apart) forces. After the nut has been turned onto the bolt, additional torque causes the nut to turn and stretch the bolt. When the bolt stretches it becomes…