No, ARP bolts are not torque to yield (TTY). TTY fasteners, when being torqued, actually stretch because of the elastic properties of the material. This gives them the needed clamping force, but the downside it that they aren’t reusable (well, at least they shouldn’t be reused).
Contents
- 1 How many times can you torque ARP bolts?
- 2 Do you have to replace torque to yield bolts?
- 3 What happens if you reuse a torque to yield bolt?
- 4 Can you reuse Headstuds?
- 5 Can I reuse ARP flywheel bolts?
- 6 How do you calculate the yield strength of a bolt?
- 7 What does tighten to yield mean?
- 8 How many times can torque to yield bolts be used?
- 9 How do you tighten torque to yield bolts?
- 10 Why do manufacturers use torque to yield bolts?
- 11 Can I reuse torqued bolts?
- 12 Can you use torque-to-yield bolts twice?
- 13 What happens when you over tighten bolts?
- 14 Do you have to replace stretch bolts?
How many times can you torque ARP bolts?
Generally bolts/studs that have a specific torque value to tighten to are reuseable, but bolts that you torque then turn an extra 1/4 turn or a number of degrees are torque to yield bolts and shouldn’t be reused more than once.
Do you have to replace torque to yield bolts?
These bolts cannot and should not be reused due to the stress caused to the bolt during its first installation. Torque-to-yield bolts may break if reused or become loose over time.
What happens if you reuse a torque to yield bolt?
Torque-to-yield (TTY) head bolts are designed to stretch when 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.
Can you reuse Headstuds?
Head bolts removed from an engine running with a blown head gasket can be rusty. If a head bolt is rusted it should not be reused. A head bolt should not be reused if the threads are galled or badly damaged.
Can I reuse ARP flywheel bolts?
The stock bolts stretch during installation so they ‘re not reusable – this set of bolts is not only reusable but actually costs about half as much as a new set of Toyota bolts.
How do you calculate the yield strength of a bolt?
Yield Strength Take the minimum yield in psi of the ASTM grade (see our Strength Requirements by Grade Chart for this value), multiplied by the stress area of the specific diameter (see our Thread Pitch Chart). This formula will give you the ultimate yield strength of that size and grade of bolt.
What does tighten to yield mean?
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.
How many times can torque to yield bolts be used?
Torque to Yield (TTY) fasteners are used in many modern engines. When torqued properly, they provide better clamping force than standard fasteners. All TTY bolts are 1-time use only. However, some rod bolts and main cap bolts can be tightened up to 3 times for assembly purposes.
How do you tighten torque to yield bolts?
How to tighten torque to yield bolts
- Tighten all bolts in sequence, and in two stages to a snug torque value of say, 30 Nm.
- Apply a 90 degree rotation to all bolts in the proper tightening sequence.
- Apply a further 90 degree rotation to all bolts in the proper tightening sequence.
Why do manufacturers use torque to yield bolts?
Many vehicle manufacturers use torque to yield bolts; especially on engines with aluminum heads and or in conjunction with (MLS) head gaskets. Because, they provide more consistent clamping loads, across the entire head-to-block mating surface. Reusing the old bolts, can cause expensive engine failure.
Can I reuse torqued bolts?
When the time comes to dismantle or reassemble, the question of whether or not to reuse nuts and bolts tends to come up. It is possible to reuse fasteners in some cases. However, only fasteners that have never been torqued beyond their yield strength may be used again.
Can you use torque-to-yield 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.
What happens when you over tighten bolts?
Everyone who has ever worked with fasteners has accidentally messed one up at some point. One of the most damaging ways to do that is by over-tightening, or over torquing the fastener. This can result in stripping screws, snapping screw heads and damaging pre-tapped threading.
Do you have to replace stretch bolts?
The replacement bolts your dealer supplied are referred to as s-t-r-e-t-c-h bolts, because they are PERMANENTLY stretched when properly installed. This is why stretch bolts must ALWAYS be replaced, and never reused.
