A-arm bolt ID
10-22-2008, 01:58 AM
#1
Nordschleife Master
Thread Starter
A-arm bolt ID
This is a Springer special: updating the A-arm bushings tonight revealed these two bolts as the arm's pivot fasteners.
The grade 8.8 is in double shear, the 10.9 is in cantilevered single shear.
Springer, what more can you tell me about them? Mfr? Fsu? (you know -- all that gnarly stuff you hold at your beck and call
)
It's only engineering curiosity on my part.
Thanks!
and how they're used
The grade 8.8 is in double shear, the 10.9 is in cantilevered single shear.
Springer, what more can you tell me about them? Mfr? Fsu? (you know -- all that gnarly stuff you hold at your beck and call
)It's only engineering curiosity on my part.
Thanks!
and how they're used
10-22-2008, 06:14 AM
#2
Addict
Rennlist Member
Rennlist Member
Both appear to be industry-standard metric cap screws. VERBUS and 3F are the manufacturer's mark. I have never heard of them, but that is a good sign (problems tend to come my way). Property Class 8.8 is medium-carbon steel, heat treated, quenched and tempered. Same metallurgy as SAE Grade 5 bolts with the three radial dashes on the head. Tensile strength is 120,000 psi minimum
Property Class 10.9 is chrome-moly steel, heat treated, quenched and tempered. Same metallurgy as SAE Grade 8 bolts. Tensile strength is 150,000 psi minimum. Ductility requirements are also greater than Class 8.8. Alloy steel resists corrosion slightly better than carbon steel, but both bolts are chromate coated, and will last a long time before they start to rust.
You can usually substitute a stronger bolt without issues because dimension requirements are identical. Never move down a grade for obvious reasons. Moving up wastes money and resources. Quality control on the stronger bolts is usually better if you want to rationalize. Possibly the assembly is designed to fail soft, meaning it is important that the bolt fail at its intended load before a more expensive or safety-critical part fails. 8.8 and 10.9 are so close in strength that I doubt that is a factor in this case.
Property Class 10.9 is chrome-moly steel, heat treated, quenched and tempered. Same metallurgy as SAE Grade 8 bolts. Tensile strength is 150,000 psi minimum. Ductility requirements are also greater than Class 8.8. Alloy steel resists corrosion slightly better than carbon steel, but both bolts are chromate coated, and will last a long time before they start to rust.
You can usually substitute a stronger bolt without issues because dimension requirements are identical. Never move down a grade for obvious reasons. Moving up wastes money and resources. Quality control on the stronger bolts is usually better if you want to rationalize. Possibly the assembly is designed to fail soft, meaning it is important that the bolt fail at its intended load before a more expensive or safety-critical part fails. 8.8 and 10.9 are so close in strength that I doubt that is a factor in this case.
10-22-2008, 01:36 PM
#6
Nordschleife Master
Thread Starter
nope, but I'm thinking it's an M12 (coarse?), 'cuz I used a 3/4" socket on both hex heads and nuts.
(Making the flat-to-flat from 18.00-17.6-ish mm)
Length or grip length? God knows, as I sit here.
(Making the flat-to-flat from 18.00-17.6-ish mm)
Length or grip length? God knows, as I sit here.
