bolts

www.arp-bolts.com/pages/technical_metallurgy.shtml
since this has been brought up lately i figured id go right to the source and see what they have to say about strength abilities of differant fasteners.
call me crazy but id say 170,000 psi is pretty damn tough for any bolt

Uh Oh, here we go with the hydrogen embrittlement issue again: :evil:

ARP2000®: ARP2000 is an alloy steel that can be safely heat treated to a higher level, producing a greater strength material than 8740. While 8740 and ARP2000 share similar characteristics – ARP2000 is capable of achieving a clamp load at 220,000 psi. ARP2000 is used widely in short track and drag racing as an up-grade from 8740 chrome moly in both steel and aluminum rods. Stress corrosion and hydrogen embrittlement are typically not a problem, providing care is taken during installation.

I wonder what the "special alloy" Stainless 300 is really made of? I guess if you had ARP make your mount bolts out of that stuff then they would be an improvement over the stock bolts. I'm bettin' that whatever there "special alloy" is, they ain't telling. It's like the Colonel's 11 herbs and spices or the formula for Coke.

STAINLESS STEEL: Ideally suited for many automotive and marine applications because stainless is tolerant of heat and virtually impervious to rust and corrosion. ARP “Stainless 300” is specially alloyed for extra durability. It’s polished using a proprietary process to produce a beautiful finish. Tensile strength is typically rated at 170,000 psi.

I'll grant you that the stainless is an improvement over the stock bolts, but it is the lowest tensile strength option that they list. :whistle:

17. Define “Power Dump.”

This is a term used to define the heavy extrusion of the fastener body during forging. The part is forced into a die much smaller than the blank thereby causing a severe reduction in cross section area. This reduction of the cross sectional area is accompanied by an increase in length because metals can’t be compressed. However, power dumping or reduction, delivers a significant increase in strength properties and is part of the patented process we use to produce fasteners from 304 stainless steel with 170,000 psi UTS and AMS 5844 (ARP 3.5) with ultimate tensile strengths in the 270,000 psi UTS range with outstanding fatigue.

The comedic options here are limitless.

yeah but its 170,000 psi,can you name any other piece on your bike with a tensile strength of 170,000 psi? :laugh:

mild steel tubing,that stuff your beloved bike frame is made of has a tensile strength of 63,800 psi! :sick: :woohoo:

T6 aluminum which is a hell of a lot stronger than the stuff your aluminum swingarm is made of has a tensile strength of 46,000 psi.

regular grade 5 bolts have a tensile strength of 105,000psi and regular grade 8s have a tensile strength of 150,000 psi.
so does anybody else see a problem with bolting together a piece of material with a maximum strength of 63,800 in pretty unstressed aplication with a bolt thats rated for more than double what the frame is rated for? hell the welds holding the frame together are only rated for 60,000 psi on a good day!
THINK ABOUT IT GUYS! :whistle: :woohoo:

Biggest reason I don't like to do aluminum swingarms. A mild steel box arm is a ton more rigid than the best aluminum plus aluminum stress cracks pretty easily.

ding,ding we have a winner! :laugh:
thats why aluminum rods in top fuel motor get tossed after so many runs

Not just on a fuel car, they get changed out on a scheduled basis all the way down to single cylinder race motors, that is if you give a squirt about you motor. Been there, done that. I watched a buddy buy used aluminum rods and couldn't convince him it was like playing russian roulette with no empty chambers in the gun, you gonna loose.

Tensile - smencil... Don't need no stinking bolt.... JB weld it! :laugh: :laugh: :laugh:

Ok, are you going to have ARP make your mount bolts using their special alloy stainless? If not then regular 304 ss is more like 75,000psi and 316 ss is closer to 84,000psi. Both less than grade 5 fasteners. Aside from that, you cannot compare the tensile strength of a fastener to a mild steel frame. They experience different types of loads. Yes the bolts are in tension, so tensile strength is an apt measure of their performance. However, the frame is not simply in tension. Tensile strength is not the only qualification for material selection. Heck, bamboo can have a tensile strength approaching 72,000psi, should we make our bolts from bamboo? It's an apples to oranges comparison. Different materials fit different applications. In my opinion, yes, the ARP stainless bolts, if tested to 170,000psi are a superior fastener, but regular stainless is inferior to even grade 5 fasteners, and more expensive to manufacture.