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canadian_driver
11-20-2008, 02:00 AM
i bought some nuts today (:smt033) and they said on the box they were grade c, now ive looked around and it says that on the rockwell scale that grade C has a load of 150kgf, how does that translate into psi or normal grades like grade 8 bolts?

canadian_driver
11-20-2008, 02:12 AM
well kinda answered my own question, a grade C nut has 144 ksi which as i think equals 144,000 psi and a grade 8 bolt has 120,000 proof load, 130,000 min yield, 150,00 min tensile.

but i dont know what the grade c kgf applies to.

ATL ZJ
11-20-2008, 10:05 AM
Did you buy them from mcmaster? I ran across this yesterday while shopping for a deformed thread dana 60 pinion nut (7/8-14). The only one they had in that size and style was Grade C. I didn't know what that meant, so I started searching around. The charts I saw placed it between grade 5 and grade 8, so I'm guessing its strength is sufficient for most uses.

edited for possibly inaccurate content

rstrucks
11-20-2008, 10:43 AM
i bought some nuts today (:smt033) and they said on the box they were grade c, now ive looked around and it says that on the rockwell scale that grade C has a load of 150kgf, how does that translate into psi or normal grades like grade 8 bolts?

Never heard of grade C. What ya bolting together?

canadian_driver
11-20-2008, 11:52 AM
i bought it from fastenal, its also a deformed thread (they call it a top lock) nut for mounting my brake caliper brackets, i know it probably doesnt need grade 8 hardware, but i dont wanna cheap out on my brakes

ATL ZJ
11-20-2008, 12:05 PM
OK I think that the Grade C terminology may just refer to the fact that these are deformed thread, top lock, or prevailing torque nuts. Every listing for "Grade C nut" that google produced has deformed threads of some type.

Ken L
11-20-2008, 12:57 PM
I looked in my Pocket Ref book and coudn't find "Grade C". I found Grades A, B, S, T and V.

elmer_fud
11-20-2008, 01:35 PM
I am wondering if grade C has something to do with how the treads are cut or the type of threads. Here is a screenshot of the powerpoint from my machine design class. I will try and look in my book tonight.

http://i260.photobucket.com/albums/ii12/elmer_fud/jeep%20forum/boltproperties.jpg

ATL ZJ
11-20-2008, 01:42 PM
Thread pitch is measured independently of material grade. But to be fair, it seems that this "Grade C" designation is referring to the distorted shape of the threads.. http://www.fastenermart.com/html/500320000080.html


http://www.imperialinc.com/pdf/A_FastenerTorqueCharts.pdf


.

elmer_fud
11-20-2008, 08:34 PM
I looked in my book like I said I would. I did not see anything about grade c. All the material strengths are listed as numbers. I did find a figure that shows different type of threads on self tapping screws identified with letters though. The links that ATL ZJ posted look like elliptical locking nuts, and I think he is right about it being the type of nut.

I took pictures of these pages, and they are shown below

http://i260.photobucket.com/albums/ii12/elmer_fud/jeep%20forum/PB200269.jpg

http://i260.photobucket.com/albums/ii12/elmer_fud/jeep%20forum/PB200270.jpg

http://i260.photobucket.com/albums/ii12/elmer_fud/jeep%20forum/PB200271.jpg

http://i260.photobucket.com/albums/ii12/elmer_fud/jeep%20forum/PB200268.jpg

http://i260.photobucket.com/albums/ii12/elmer_fud/jeep%20forum/PB200272.jpg