black coated studs

[pyroracing85]

What is the coating when the bolt is black? What material do they start out with?

thanks for the help

[Ken_Shea]

It is more then likely a black oxide finish.

Here is a link that explains a little.
http://www.cnczone.com/forums/showth...ighlight=oxide

[pyroracing85]

Do they start out with stainless? I am working on a program to machine a special stud for a wheel

[2muchstuff]

Bolts with a black oxide coating on them are a steel bolt. Hex head bolts follow other bolts regarding grading, hash marks on the head. I believe that allen head cap screws are a grade 8 bolt.

[pyroracing85]

I dont want to machine hex just round stock cause i'm making a uniqure stud one without a head or allen head.

[themachinest]

No black oxide on stainless, sorry.

[pyroracing85]

thanks. I am still writing this program for a bolt

[Fish]

Hey Pyro,

Go to the ARP fastener site. They have tons of info on materials and processes (at least they do in their catalogue). You might want to start from a finished bolt or something so you don't have to mess around with heat treating and oxiding. It will just take a little longer to machine.

What kind of wheel are you trying to fasten? What is the application? Choosing the material to make it from will depend on the strength needed.

Fish

[Splint]

There is a chemical process (sorry cant recall the name) which is sold in kit form at a price suitable for the hobbiest. The only issue with this stuff is that sometimes the solution dose not give an even consistant finish, it shows runs. If I can find the brochure I'll post the name of the stuff.

[lerman]

When I'm wearing a Tuxedo.

:-)

[Splint]

www.blackfast.com I saw a demonstration of this product at a trade show a few years back, seemed to work pretty well.
Splint