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pyroracing85
02-15-2005, 12:23 PM
What is the coating when the bolt is black? What material do they start out with?

thanks for the help

Ken_Shea
02-15-2005, 12:53 PM
It is more then likely a black oxide finish.

Here is a link that explains a little.
http://www.cnczone.com/forums/showthread.php?t=8175&highlight=oxide

pyroracing85
02-15-2005, 09:34 PM
Do they start out with stainless? I am working on a program to machine a special stud for a wheel

2muchstuff
02-15-2005, 10:04 PM
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
02-15-2005, 10:06 PM
I dont want to machine hex just round stock cause i'm making a uniqure stud one without a head or allen head.

themachinest
02-16-2005, 10:49 AM
No black oxide on stainless, sorry.

pyroracing85
02-16-2005, 12:39 PM
thanks. I am still writing this program for a bolt

Fish
02-18-2005, 01:36 AM
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
02-18-2005, 02:54 AM
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
02-18-2005, 07:48 AM
When I'm wearing a Tuxedo.

:-)

Splint
02-19-2005, 09:11 AM
www.blackfast.com I saw a demonstration of this product at a trade show a few years back, seemed to work pretty well.
Splint