Frame restoration bolts

[Steelydan]

Hey everyone I’m in the process of getting ready to start reattaching my crossmember to the frame and many other parts. What has eveyone use for bolts to do this? Thanks in advance
Posted via Mobile Device

[Mr Handy]

Any time I removed rivets from the frame I replaced them with grade 8 hardware.
I am also fond of serrated flange nuts for this kind of stuff.

[LockDoc]

Originally Posted by Steelydan

Hey everyone I’m in the process of getting ready to start reattaching my crossmember to the frame and many other parts. What has eveyone use for bolts to do this? Thanks in advance
Posted via Mobile Device

Grade 8 bolts and hardware, and make sure they fit in the holes snug. I drill all of mine out so 7/16 bolts fit snug.....

LockDoc

[crakarjax]

+1 to grade 8, I use flat washers on each side to save my paint and prevent rust and also use red loctite -- NO lock washers. Prime and paint over the bolts and washers afterwards.

[kwmech]

Originally Posted by crakarjax

+1 to grade 8, I use flat washers on each side to save my paint and prevent rust and also use red loctite -- NO lock washers. Prime and paint over the bolts and washers afterwards.

I agree, no lock washers. I use the pinch type self locking and fine thread bolts. Torque 'em to 70lbs

[71CHEVYSHORTBED402]

Subject recently came up someone's undercarriage had the wrong bolt finish (i.e., some hardware was not phosphate coated).

From what I see, you don't have much choice in the matter. Take the axle plates for example. They're (GR 8) 9/16" hex bolts, lock washers and nuts. The bolt threads are 3/8-24 x 1.

Unless you can locate NOS, where are you going to find that in anything other than stainless or yellow zinc? I suppose you could attack the zinc and have them coated. I'm on-board with the factory look & parts, and that's my goal, but if you ask me, yellow zinc works.

[beaterku]

You can get black phosphate bolts from Mcmaster.

[Steelydan]

Thank you everyone for the replies I am wanting to keep the truck as close to original as I can.

[indymachinist]

I buy a lot of "truck part" hardware from mcmaster. But I'm not afraid of yellow zinc hardware on mine.

[B. W.]

I used hex head flange bolts (also called frame bolts) on my crossmembers. Also did what LocDoc said: drill out to 7/16" where possible. The holes were so wallowed out on my engine crossmember (old 4x4 farm truck) I had to weld up the holes & re-drill to 3/8" because I had clearance issues with 7/16".

I've taken yellow zinc hardware, bead blasted it then re-finished in a black phosphate home brew. It comes out out looking good but is a lot of work. Add to that, I think the zinc coating provides better protection.

I use McMaster a lot also.

[Spf79]

I went with stainless grade 8 bolts and lock nuts.

[crakarjax]

I hope those are ARP because afaik they are the only manufacturer of stainless that is as strong as grade 8

[Spf79]

Originally Posted by crakarjax

I hope those are ARP because afaik they are the only manufacturer of stainless that is as strong as grade 8

I got them from a bolt supply house I deal with through work. I sell a lot of bolts, mostly large diameter flange kits for piping, so my knowlege is limited. I appreciate the heads up, I will look into this, better safe than sorry.

Have a good night!

[Steelydan]

Originally Posted by B. W.

I used hex head flange bolts (also called frame bolts) on my crossmembers. Also did what LocDoc said: drill out to 7/16" where possible. The holes were so wallowed out on my engine crossmember (old 4x4 farm truck) I had to weld up the holes & re-drill to 3/8" because I had clearance issues with 7/16".

I've taken yellow zinc hardware, bead blasted it then re-finished in a black phosphate home brew. It comes out out looking good but is a lot of work. Add to that, I think the zinc coating provides better protection.

I use McMaster a lot also.

Looks great where did you find 7/16 black phosphate nuts at.....? I am having trouble finding that size of nut in the black phosphate?

[71CHEVYSHORTBED402]

Originally Posted by Steelydan

Looks great where did you find 7/16 black phosphate nuts at.....? I am having trouble finding that size of nut in the black phosphate?

Anyone ever use black oxide stainless steel? Has a nice look. McMaster_Carr carries black oxide stainless steel 18-8 nuts. Can't say if they're automotive quality.

Black phosphate replacement nuts and washers would be great, but I'm missing them. That's partially because can't make out what "18-8", and "18-10" nuts are. Seems to me you want an equal nut and washer for a Grade 8 bolt. In other terms, how does 18-8, 18-10 or other suit a Grade 8 bolt? Grade 5 as well.


I believe original hardware is manganese phosphate. Here's a website that explains the difference between that and zinc phosphate. Judging by the photo, I'd say the nuts are zinc phosphate, and beautiful finish. IMO it's superior in appearance. Likely more corrosive resistant too. Might bring a bit too much shine to under the hood, but would make for a beautiful under-carriage, IMO http://imf-co.com/portfolio/phosphat...houston-texas/

[indymachinist]

18-8 and 18-10 is the amount of chromium and nickel the stainless has in it. It's not a grade like 5, 8, etc.

[71CHEVYSHORTBED402]

Originally Posted by indymachinist

18-8 and 18-10 is the amount of chromium and nickel the stainless has in it. It's not a grade like 5, 8, etc.

Understood, but how do they match up to Grade 5 & 8?

If you go to the hardware store, they have "grade 8" nuts and washers for grade 8 bolts. The same doesn't seem to apply for grade 5 bolts. I suppose that means standard nuts and washers work for grade 2 and grade 5 bolts.

[crakarjax]

Originally Posted by 71CHEVYSHORTBED402

Understood, but how do they match up to Grade 5 & 8?

If you go to the hardware store, they have "grade 8" nuts and washers for grade 8 bolts. The same doesn't seem to apply for grade 5 bolts. I suppose that means standard nuts and washers work for grade 2 and grade 5 bolts.

My store has grade 5 and 8 nuts, and you can get matching washers but the strength on those isn't critical. 18-8 is weaker than grade 5.

[mike16]

I think the best they can do in terms of strength is a little bit more than grade 5.

There are vendors who deal with the NCRS crowd that actually sell the factory rivets, you have to heat them up and install them yourself .

[indymachinist]

When looking at bolts on mcmaster.com compare tensile strength of the bolts like grade it said 150000 and 18-8 said 70000

[B. W.]

Originally Posted by Steelydan

Looks great where did you find 7/16 black phosphate nuts at.....? I am having trouble finding that size of nut in the black phosphate?

I believe I bought them here:

https://www.nutty.com/Grade-8-Hex-Fl...uts_c_367.html

[Steelydan]

Thanks for all the great replies I think I have it all figured out what I’m going to use once everything gets back from being powder coated. Does anyone happen to know the size of the bolt for the Panhard bar to the frame. I misplaced the original one and would like to order all my bolts at one time rather than separate orders. Thanks in advance

[volksworld]

an actual grade 5 nut will have 3 little depressions on the face like the 3 lines on the head of the bolt...find a better hardware store....