The Stovebolt Site Forums The Shop Area Engine Shop Learn me about bolts please

Over the years I occasionally had a bad bolt or nut that needed replaced. I know there is the grade 5 with 3 bars on the head, and grade 8 with 5 bars. So I go to the big box store and have two choices….. either zinc or stainless steel. I know that two different metals are usually not compatible and tend to gall. I want the “black” automotive style bolts/nuts like what came in our old trucks. They also look original and don’t stick out like sore thumbs. As an example, I’d like to replace all of the nuts on top of the rocker arms. After 70 years of wrenching on them to adjust valve lash they are pretty buggered up. Where do you guys & gals go to buy this kind of hardware? Thanks

Check mcmaster carr. They have lots of options on hardware.
Link

Ebay has untold thousands of bolts and nuts in every size and grade imaginable. You just need to know exactly what you're looking for. Those stovebolt rocker arm locknuts will be 7/16-20, but they're about half the thickness of regular nuts.

For instance:

https://www.ebay.com/itm/390127261719?

Jerry

For black-oxide bolts, I usually go to a True Value Hardware if I just need a couple or Fastenal/McMaster if I need a lot.

Kevin, Jerry, and Fibonachu…… thanks for the suggestions and links for black oxide bolts. I didn’t really know what to call them, but now I do and where I can buy them. Much appreciated!

Jerry, thanks for reminding me that those particular nuts are different in size and are referred to as jam nuts.

If you want to learn about nuts & bolts (& so much more) go to Pegasus Racing, their catalogs cover it, grip lengths, 12 point, AN, grades, nyloc, jam,etc etc, if you were building a car from scratch their catalog is the required shop reference…
Probably have your jam nuts available in 12point

McMaster Carr has everything to make about anything and they will get it to you spooky fast. If you want to go top of the line ARP is the way to go. They are designed to be retorqued. A standard bolt can only be torqued once and be in spec.

Update…. I drove to three nut & bolt retailers today looking for the elusive 7/16-20 black oxide jam nut with no luck. Only one store had any in stock, but they were zinc and the outer circumference was much larger than the Stovebolt nut. I went online and found a bag of 25 stainless steel nuts for less than $10 with free freight. My question is will they be compatible with the steel rocker adjusting screws? I’ve always heard different metals gall. Logic tells me they would be okay because of the constant drip of oil.

I don’t believe you will have much luck finding these nuts, in the proper size and proper grade outside of the automotive trade. Personally, I would buy originals or buy the exact replacements.

Not cheap, but the Filling Station has the studs and nuts as a kit. Here is a [LINK]

I see them on eBay occasionally. Good luck with your search.

Put a little Never-Seez on the threads and drive on. Stainless tends to friction weld itself together when bolts and nuts of the same alloy are torqued tightly, but I don't think I've ever seen carbon steel and stainless fasteners gall when they're used together.
Jerry

Spotbiltxo If you read the GM service books I think you'll see that Chevy recommends replacing those rocker nuts,which are designed to lock in place the first install. Very much adjusting and they kinda loose their grip,gotta remember they built engines to sell !!

ARP and braided lines are what melted your budget and gained nothing.

McMaster-Carr is a decent retailer, MSC Industrial Supply is better.

Probably neither will have a half-thickness nut in a 7/16 x 20, although I do not know that. as I do not need that size.

Stuff like that generally has to be custom-made. We used to put body screws in our carburetor kits, and odd sizes (13/16 instead of 3/4 or 1 inch) generally had to be special-ordered with a minimum of from 5000 up. We quit putting body screws in our kits when the U.S. suppliers went out of business. I will not use the junk.

Not a big fan of stainless fasteners; but if you are, don't EVER use them with a zinc alloy a.k.a. pot metal part (i.e. carburetor body) unless you wish to buy a new carburetor every time yours needs rebuilding. Or you just REALLY enjoy heli-coiling every screw hole!

If you find the fasteners in the correct size, but wrong finish; you can chemically strip the finish and apply the black oxide, assuming you are doing a restoration where finish is important.

Jon.

1. You will never need SS unless for shine somewhere. Pan head and oval head trims screws are SS.
2. On our old trucks, except for a few motor, driveline and suspension hardware, you can torque them as many times as you need to.
3. The only nuts you should not use twice are locking nuts. Nylon, deformed thread....
4. When dismantling a truck or motor, always save and reuse the hardware. Lock washers can be reused if not flattened. Rusty OK, Rusted no.
5. Grade 5 is all you will ever need.
6. McMaster Carr seems to have Gr 5 black oxide fasteners. Limited length bolt choices. Nuts no problem. Large quantities only?. EBay sellers buy these and break into small Qtys.
7. Could not navigate to black fasteners at MSC Industrial Supply.

Here is a bunch of choices for 7/16 jam nuts. They are way faster than Amazon. https://www.mcmaster.com/jam-nuts/

You can't be faster than Amazon prime.

Bart - they have so much stuff you have to keep refining your search; but if you are patient and go through fasteners, nuts, hex nuts, hex jam nuts, and then scroll down on the left column, you will find finishes at the very bottom. Black oxide is listed.

Jon.

Have you ordered from Amazon lately? Prime guaranteed tomorrow delivery means between a week and never around here.

I have ordered stuff from McMaster in the afternoon and received it the next day at no additional cost. It's spooky.

I couldn’t find black oxide 7/16-20 jam nuts for sale on the McMaster-Carr website, so I ordered a bag of 25 stainless steel nuts off FleaBay. Should be here by Saturday.