I found this chart among my dad's things. Never heard of grade "super" fasteners. Aerospace industry, maybe? Must have been used on the "Encabulator".

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  grade super.JPG (146.86 KB)

must have been to hold in a "full race" cam

WTF? I call b.s.

http://www.americanfastener.com/technical/grade_markings_steel.asp

Wow first time I seen or heard of a super grade fastener. What year is the print date on the craftsman chart?

Mike

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Hmm. That shows ASTM A574 bolts as 20% stronger than grade 8.

But it applies to socket head cap screws.

No print date, but the back side has torque specs for Sears motorcycles. Remember them?

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How can you call bs? That card is probably 50 years old. When did the bolt sizes/strength indexes become standardized? Perhaps in the 50s/60s - whenever that card is from, that was an available bolt. There are bolts currently stronger than grade 8 now, they just have different names than "super grade".

As far as the OP, neat find.

Matthew

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Where?

Look at the chart you posted.

proof load Yield Strength Tensile Strength
SAE J429
Grade 8 120,000 130,000 150,000

A490 120,000 130,000 150,000 min
ASTM A490 170,000 max

OR

ARP head bolts that are claimed to be 15 % stronger than grade 8 (170,000 psi).

OR

8640 alloy bolts:
180,000 - 190,000 psi tensile strength
http://www.f911.com/fore2.html http://www.f911.com/fore2b.html

OR

Various manufacturers in the machine industry producing bolts for different applications

OR

European standards

Metric 12.9 yield strength 156,000 tensile 175,000


Here's a good article:

http://www.pirate4x4.com/tech/billavi ... lts/Nuts&Bolts_signed.pdf

Matthew

Some good info in that last article, I'll read it in depth later.

I know there's stronger bolts out there, but it's ridiculous to refer to "super alloy" on a chart. Sears doesn't make bolts and there is no super alloy. There is no such standard either, so I have no idea who'd use that chart for anything. If you're using a kryptonite bolt from ARP, use ARP's chart.

Those 8640 alloy bolts have a bunch of standards listed, which I guess might impress someone that doesn't know what they mean, but the only meaningful one is that they comply with the ASTM Class 12.9 standard. All the other standards listed just refer to dimensions, or Grade 8 standard which is weaker.

So basically they sell SAE bolts that meet the Class 12.9 strength standard.