Can I use stainless bolts for manifolds? Will they take 35 lbs. of torque, or must I use steel Grade 5/8? Do they make Grade 5/8 stainless bolts?

Thanks in advance,

D. Ocean
Pompano Beach, FLA

i use stainless bolts for my stellings and they seem to work just fine

ARP makes them. They are 10% stronger than grade 8 to hold your manifold in place and beautiful to hold your admiring gaze. Go get em!

The strength of stainless steel is like any steel, there are lots and lots of different alloys with a range of properties. Most common is a 300 series SS. Plus the diameter makes a difference , but I cannot imagine that a stainless bolt would not take the stress of 35 ft-lb. What size bolt is it? I could put lots of dorky equations on here to show you how to calculate the stresses, but I will save everyone the trouble of demonstrating my dorky-ness.

I visited a local bolt supply house yesterday and, according to their charts, a typical S/S 3/8" x 1 1/2" bolt is rated at only 263 in/lbs. of tourqe (21.829 ft/lbs.) That isn't close to 35 ft/lbs that I need for the manifolds.

I'll check with ARP.

D. Ocean
Pompano Beach, FLA

Better double check your info. Way off.

My nut and bolt supply house tells me that I can get grade 8 stainless nuts and bolts... I prefer allen cap screws myself... but you have to spec higher grade bolts than what you get at home depot of OSH hardware..... Some of the high strength stainless alloy bolts won't polish to a high gloss... keep that in mind.. they will be somewhat grey in color.

1 in. pounds = 0.0833333333 feet pounds

263 in. lb x 0.083 = 21.829 ft. lb

???

D. Ocean
Pompano Beach, FLA

make sure apply never seize. reason two dissimular metals.

The guys at my local bolt house just looked at me funny when I asked for grade 8 stainless. "No such thing" was their unanimous reply.

Guess I'll have to contact ARP.

I wouldn't take bolts from HD if they were giving 'em away.

D. Ocean
Pompano Beach, FLA