What is the purpose of bolt tightening?

What is the purpose of bolt tightening?

A proper bolt tightening sequence in flanged joints is essential to control stress variation in flange joint components. Otherwise, leakage occurs at flanged pipe joints during operating conditions. Most joint surface of joints is not completely flat.

Can you reuse torque-to-yield head bolts?

Why shouldn’t torque-to-yield head bolts be re-used Once stretched, they are not as strong as before. Consequently, they cannot provide the same amount of clamping force and may break or shear off if reused. Because the tightening procedure permanently stretches the bolts, there is a risk of breakage if reused.

How many times can you stretch a bolt?

Typically, the amount of stretching may be as little as 0.001-in. In most cases there is no way to know whether or not the fastener has yielded, so, it is advisable to never reuse fasteners in critical applications.

How does a stretch bolt work?

A torque to yield fastener (TTY) or stretch bolt is a fastener which is torqued beyond the state of elasticity and therefore undergoes plastic deformation, causing it to become permanently elongated.

Do I need to replace stretch bolts?

If you remove any torque to yield bolts (Stretch bolts), you SHOULD replace them with new bolts and torque to specification. stretch to ensure proper securing when tightened down.

Can you use stretch bolts twice?

However, because the tightening procedure does permanently stretch the bolt, there is some risk of breakage if the bolt is reused. And since there is no way to tell how many times a bolt has been reused, it doesn’t make any sense to reused TTY bolts – the risk far outweighs the replacement cost of used bolts.

Can you reuse VW head bolts?

Registered. You can reuse the 6 point head bolts as they are not stretch bolts. If it has 12 points, you can not reuse them.

Can you reuse ARP head bolts?

Are ARP bolts and studs re-usable? Yes. As long as the fasteners have been installed and torqued correctly, and show no visible signs of damage, they can be re-used. If they show any signs of thread galling or corrosion, they should be replaced.

Can you reuse Hemi head bolts?

Therefore, it’s probably safe to reuse the original head bolts assuming they are not TTY head bolts (which should not be reused). On a high mileage engine, or a performance engine, it’s risky to reuse the original head bolts because the engine may have been torn down several times already.

Can you reuse Duramax head bolts?

They are reusable and have a much higher fastening torque.

How do you reuse head bolts?

Tips for Reusing Head Bolts

1. Clean and Inspect. Because of the intense heat that the head is in, the bolts will occasionally fail when torque is applied to remove them.
2. Soak in Oil. After you have determined the bolts are still usable, soak them in motor oil for at least 24 hours.
3. Clean Thread Holes.
4. Use Torque Wrench.