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Stainless steel fasteners


Well-known member
May 24, 2001
We Will All Meet Again
1966,and a 1962 thats almost complete
Is any one using stainless steel fastners on your project? I am looking for a source for some Grade 8 stainless nuts and bolts for a project I am doing
Almost without exception, "hot-rod" stainless fasteners are Grade 2, which is what you'd use to hang a farm gate; you'll find this little disclaimer buried somewhere near the front of the catalog, along with "Unless specifically noted otherwise". Don't even THINK about using "stainless" fasteners unless you get them from ARP, SPS, or other specialty fastener manufacturers; I've used hundreds of ARP fasteners in all sizes and lengths on many project cars over the years, and still have an enormous inventory on hand. ARP can supply almost any fastener you'll ever need ( www.arp-bolts.com ); they're the ONLY stainless fastener supplier I'd use. They're expensive, but they're the best in the business, and everything they sell is Grade 8-equivalent or better.

Scares hell out of me when I go to a show and see all the Grade 2 "hot-rod" catalog no-name/no head-marking stainless and chrome-plated bolts being used in critical steering/suspension/brake applications, only for the sake of appearance :(

In addition to ARP, there is a company called Totally Stainless that sells stronger than Grade 8 stainless fasteners in fractional sizes, and is starting to sell Metric sizes. In their smaller sizes, they just sell ARP fasteners, but in the larger sizes, they make their own. ARP is somewhat limited in their sizes and primarily supplies the smaller sizes. Totally Stainless sells even large sizes in both high strength and low strength. You will find that the high strength bolts required for the suspension on your chassis will be fairly expensive. I have several hundred dollars in the bolts on my chassis. If memory serves me right, the 2 8" X 5/8" bolts for the shock mount were almost $30 each! These were by far the most expensive, but most bolts were at least a couple of bucks each. They are, as far as I know, the only vendor that sells high strength stainless in larger sizes.
I converted most of the metric size bolts on my running gear over to fractional sizes since they did not make much high strength in metric at the time. I would guess that you would still have a hard time finding all the sizes that you need in metric, and would pay a premium for them as well. I used high strength bolts in places where they were not even needed in order to keep a uniform look to the bolts.
The high strength bolts all have a reduced size hex head, while their low strength bolts are only available in full hex, internal hex button head, and standard allen head. I am using the button head fasteners a lot on the body and for areas like mounting lines and clamps as well all the fasteners under the hood with the exception of the engine bolts. I buy these bolts by the dozens, and most of them are only a few cents each. They all polish up to a chrome-like appearance with little effort. Get one of their catalogs, and you will be impressed with the selection of hardware. They must have at least 5 flat washers for each size bolt with different outside diameters and thicknesses! They also have a lot of special stainless bolts like the flange head bolts that are used so much on C1 cars.

Regards, John McGraw
Thank Guys I will contact both today to question about the strenghts. And to order catalogs.Once I get my rear shocks installed I can then remove each bolt and nut and measure it then order them all at once for re assembly.
Good idea on waiting until you have everything together before ordering bolts.
I used cheap grade 2 bolts to mock everything up,and then oredered my bolts a little long and trimmed every bolt off so that about 2 threads was left sticking out of the self-locking nut and then polished the end of the bolt! I know that this is kind ao anal, but it is only time, and it is not like it is costing me anything! LOL
It sure looks nice having all the bolt tails the same when you look under the car.
One word of advice. The use of never-seize is an absolute must when torquing stainless bolts of this size up the the kind of torques that are necessary, if you ever want to get them off again! I put a shock mounting bolt in one night, and was too lazy to walk across the drive to the other shop to get the never-seize. Well, I went to take the bolt out an hour later, and it loosened about 2 turns and then galled solid to the nut. I had to take a large break over bar and crank on the bolt until it snapped! Stainless is absolutely unforgiving when it comes to gaulling, and it is aggrevated by the use of self-locking nuts.

Regards, John McGraw
I bought ARP's SS engine bolt kit and must say they are the nicest SS bolts I've seen. They look almost chrome plated. Hard to believe they still have the strength.
I've been thinking about a set of stainless intake bolts for my project. I need to get some anyway. I'll take a look at the ARPs.

I'll take John's word regarding the galling problem that he associates with SS fasteners, but to tell you the truth, it's all I have on my engine and I have yet to encounter this problem. Anti-sieze was never used - I knew no better. I did know to use it with aluminum parts, but never heard about stainless having galling problems. ;shrug
I used to use stainless socket head bolts for headers and never had a problem either. I have never used stainless in the situation where John had the gauling though. I'm all for learning from other's mistakes. It's a lot cheaper than doing it myself. :L
I'm with John on this one - an aircraft A&E mechanic told me about anti-seize on alloy fasteners MANY years ago, and I've used it on every single alloy stainless bolt I've ever used, never had any removal problems.
Let's post some tips ...

[font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]There are many “little things” to consider [/font]

[font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]1.[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular] When you use a locking chemical for studs, bolts or even nuts, consider if you really need it.

[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]2.[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular] If you are using a locking chemical, don’t force nuts off or studs out without a proper first step, like heat or release chemical.

[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]3.[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular] If you can’t easily screw a nut and bolt together by hand they shouldn’t be used.

[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]4.[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular] Consider the importance in regard to how many exposed threads are left when fastener is set. Turns out this has a bearing on necessary torque and ultimate strength of the fastener.

[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]5.[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular] Gradually try to understand and learn the difference in the various steels used in fasteners.

[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]6.[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular] Turns out, the best way to consider a fastener as a spring of correct elasticity for that specific job. Yup, a fastener works best when stretched a specific amount.

[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]7.[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular] You have got to start studying fasteners just like you do pistons, cranks, rods, etc. There’s a lot to learn if you know what to look for.

[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]8.[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular] The more you understand all the design limitations of fasteners, the better the engine durability will be.

[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]9.[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular] If you can’t stretch the bolt enough, it can still fatigue, lose torque or get loose.

[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]10.[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular] Use a stretch gauge whenever possible. This is the only fool-proof method of getting the correct clamping force.

[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]11.[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular] Get access to a master gauge to check your torque wrenches. You’d be surprised at how many torque wrenches read incorrect.

[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]12.[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular] Don’t forget that you’ll get different torque readings when using different lubricants.

[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]13.[/font][font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular] Use ARP’s moly lube whenever possible. :L[/font]

[font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]“It’s to your advantage to know fasteners.”

[font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]To thoroughly understand it all would require at least 4 specific engineering degrees and 20 years of hands on experience in each. Nothing is forever, but take my word for it, ARP® is the only game in town today. Just about every successful racer I know today uses their stuff 100%. You can help yourself in reference to material specs, thread lubes and torque techniques, also in fastener maintenance and handling. If you do a good job here, you’ll never lose position in a race from fastener failure. [/font]
For much more insight into what goes into the manufacture, application, and use of the different types of fasteners, visit ARP's Tech Page. :CAC[/font]

The gualing problem is most pronounced when a stainless bolt is mated to a stainless nut. It is even compounded by a nylon self-locking nut! It is less of a problem when the stainless bolt is installed into a cast iron threaded hole, and lube of any kind makes the problem much less. Surprisingly, the manufacturers also reccomend purple thread locking compound as an option to an anti-seize compound. The thread locking compound must offer some lubrication to the threads as you unscrew them. It is however, allways a good idea to coat the threads with a anti-gauling compound anytime you install a stainless bolt. In spite of the fact that the bolt may be very strong in tensile strength, the stainless material is much more ductile than standard steel, and the threads will grab at an unlubricated surface and will actually wipe the threads away. Once this happens, the bolt will lock itself to the nut and will never come off!

Regards, John McGraw

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