Rear Sub-Frame Bolts - In Stainless Steel - Extras for sale
I did not enjoy removing the one rear sub-frame bolt I needed to.
So screw this rusty crap, I'm having Stainless Steel bolts made.
M12 x 1.75 x 130mm , Ø20mm flange, 14mm wrench (across the flats)
Hot forged head, rolled threads, chemically ected.
And yes I'll have to order 100~500 bolts.
The common stainless steel bolts grades are too soft.
Common metric grades are ...
304 like material is used to make A2 grade bolts
316 like material is used to make A4 grade bolts.
But it's not that simple.
It turns out that you can heat treat stainless to different class. So a A4-80 is stronger than a A4-70 bolt.
We could use an A4-100 bolt , if we could find one.
Since I could NOT find one in our size, I've having them made.
The bolts I'm having made are not 304 or 316 which are 18-8, but closer to 17-4.
17-4 is a semi austenitic precipitation hardening grade of stainless.
What's important is the tensile , yield and shear strength will be higher than the 10.9 epoxy coated steel bolts we are currently using.