bolts

ok heres your apples to apples comparison.
good ol grade 2 steel bolts 60-74,000 psi/bottem of the barrel stainless steel bolts
80-90,000 psi.
even the lowest grade stainless bolt is 1 1/2 stronger than the frame its attached to.

Torque to yield bolts like those found in most modern engines have "stretch" engineered into them. Enough so that you can only use them once and you have to buy new. The threads are also "cut" onto the bolt. ARP bolts and studs don't stretch when torqued and the threads are "rolled" on, meaning they don't remove material to make them. As far as black oxide bolts go, if you want to repeatedly put money into fasteners that are exposed to the elements, use them, if not make the move to stainless. Stainless is more brittle, meaning it is more likely to break than it is to stretch, but since we are all so keen on torque procedures and tensile strength you'll never over torque the stainless and break it.

My electric bamboo bike:



:woohoo: :evil:

T_Dub wrote: Any M8 bolt will snap off with a 3/8 ratchet, doesn't matter what you have. Tensile strength is one thing, but as soon as you start twisting it you go into a torque regime, and the stress induced by torque is magnitudes higher than an axial force, which the bolt is designed for. Thats why bolts have a toque rating that might seem low, but in the case of something like engine bolts, they are usually designed to go up to 90% of the proof strength when torqued, thats why sometimes when you overtorque it seems like the bolt snaps off really easy.

My APE cylinder studs are wet torqued to 22lbs-ft in the case and 42lbs-ft on the nuts, what's the factory studs torque specs? Hers a hint, less than the APE fasteners.

TeK9iNe wrote: My electric bamboo bike:

:woohoo: :evil:

That's awesome! where does the gerbil ride?

andy9802gt wrote:

T_Dub wrote: Any M8 bolt will snap off with a 3/8 ratchet, doesn't matter what you have. Tensile strength is one thing, but as soon as you start twisting it you go into a torque regime, and the stress induced by torque is magnitudes higher than an axial force, which the bolt is designed for. Thats why bolts have a toque rating that might seem low, but in the case of something like engine bolts, they are usually designed to go up to 90% of the proof strength when torqued, thats why sometimes when you overtorque it seems like the bolt snaps off really easy.

My APE cylinder studs are wet torqued to 22lbs-ft in the case and 42lbs-ft on the nuts, what's the factory studs torque specs? Hers a hint, less than the APE fasteners.

Thereby proving my point. The APE ones are stronger, therefore they can take more load, which is their purpose. They are designed to separate at a higher cylinder pressure made by higher power machines. Thats why I have them in my bike.

BTW, my posts aren't opinions.

wireman wrote: ok heres your apples to apples comparison.
good ol grade 2 steel bolts 60-74,000 psi/bottem of the barrel stainless steel bolts
80-90,000 psi.
even the lowest grade stainless bolt is 1 1/2 stronger than the frame its attached to.

I'm not saying the stainless wont work. Nowhere did I say that. I just tried to explain a bit about bolted joint design. If you have a stainless bolt that will take the torque that the stock one will, then go for it. Stainless has other problems, such as if you have a stainless nut it will most likely gall. I think what Josh is getting at is that materials selection for important fasteners has to have more thought behind it than "oh its strong enough, it'll be fine". There are toher factors to consider when making a materials choice.

As for apples to oranges, you are comparing that when you go around saying things like the bolt is stronger than the frame it is attached to. The frame isn't a bolt and the bolt isn't a frame. Sure, from a bulk materials property perspective, the bolt is stronger, but these are mechanical components, not bulk materials. They have different loads, and different purposes in the assembly.

That all said, I hope you all have coatings on whatever aluminum you have fastened with your stainless bolts, cause it'll stain the bejesus out of it. I wouldn't put stainless on a bike either without looking into the corrosion cell its setting up.

well would you use a 16 penny nails to nail 2x2s together with? :whistle:

Hell I thought it was pretty common knowledge that stainless bolts needed anti-sieze applied to them when installed to prevent galling.

Someone stated that the ARP bolts don't stretch, on the contrary, it's that stretch that keeps the bolt or nut tight. Much like a spring holding a screen door shut. Top engine builders not only torque to a spec but also measure stretch to determine that the bolt quality is there on the connecting rods. 190 mph at the track isn't a good time to find out.

hell any time you install a stud or a head or main cap bolt youre supposed to lubricate the threads also

andy9802gt wrote:

TeK9iNe wrote: My electric bamboo bike:

:woohoo: :evil:

That's awesome! where does the gerbil ride?

look at the seat upgrade.....whoot whoooot.