How to tell if a bolt is a Torque-to-Yield (TTY) head bolt ???

[tpenfield]

I am wondering if there is a definitive way to tell if a head bolt is a 'TTY' bolt versus a 'standard' head bolt just by looking at the bolt.

Does anyone know if there are special markings on the bolts or what?

 

[Don S]

Re: How to tell if a bolt is a Torque-to-Yield (TTY) head bolt ???

The Chevy V8 Gas engines SB nor your 7.4L does not use torque to yield bolts. Newer models use angle torque, but that does not mean it's torque to yield. Torque to yield is a completely different process and usually found on diesel engines.

 

[Don S]

Re: How to tell if a bolt is a Torque-to-Yield (TTY) head bolt ???

I am wondering if there is a definitive way to tell if a head bolt is a 'TTY' bolt versus a 'standard' head bolt just by looking at the bolt.

Looking at the OEM service manual is the best way. For your engine, it says to clean the bolt threads and threads in the block before installing the head.

Now, if you go to the 496 engines, it says "USE New bolts".

While looking at the bolts as shown in the graphic bubba posted works, if you look, they both have a cut down area, you just have to know how much is cut down to know if it's a TTY or not. If you don't have both types side by side, you could replace bolts for no reason.
You basically need the manual to know what to look for.

 

[tpenfield]

Re: How to tell if a bolt is a Torque-to-Yield (TTY) head bolt ???

Most can be identified with this guide. (I say most because not all manufactures follow the guide lines.)

Perfect, thanks.