bolts

jpfletch1 · #1 (**permalink**) 06-21-2003, 02:28 PM

I am curious as to how you tell the difference between different grades of bolts.I just received an engine back from the builder and was curious as to why some of the bolts were different. On the intake manifold most of them are chrome looking and 2 of them are gold color. I thought the gold color indicated a grade 8 bolt . Is there any reason the bolts on the intake manifold should not all be the same. Additional question is, does it matter what grade bolts hold on the manifold, water pump, fuel pump ect.

Chifo Jr · #2 (**permalink**) 06-21-2003, 02:51 PM

For standard types of bolts there is a hash designation on the hex head of the bolt. Count the amount of hash on the head and add two to it to get the grade of bolt. If there is no marks on the top it is a grade 2 bolt. Three marks is a grade 5 and six marks is a grade 8 bolt. Most socket head cap screws are grade 8, unless they are in a different alloy.

BB427 · #3 (**permalink**) 06-21-2003, 02:57 PM

The gold color is just the plating/rust inhibitor that was used. Identify the grade of bolt by the number of markings on the head of the bolt. I ran into a situation using an ARP stainless steel bolt kit. 4 of the intake bolts were too short and I had to call the 800# that ARP sends with every kit to have them send me the correct length bolt. Your builder may have just put in what he had at the time????

If he used ARP they will not charge you for the replacement bolts.