has anyone ever seen a class 12.9 5/8-11 bolt? My bobcat t740 sheared the sprocket bolts, so I picked up 1 bolt from the bobcat dealer and was going to get the rest from the hardware store. It’s a 5/8-11 thread with 12.9 on the head. I thought 12.9 was iso metric grading? Would a grade 8 sae be sufficient?
You probably want to get L9 grade bolts. Tho 8s will probably hold it fine. Why did they shear. Are the surfaces not flat
I was always under the assumption that 12.9 meant metric.
Are you sure it is 5/8” x 11 TPI and not M16 x 2mm thread pitch.? They are VERY close.
Doesn't make any sense to have a metric/ SAE bolt. 12.9 metric is apparently a little stronger than a grade 8 bolt. I think it's the L9 that is similar strength but is not an SAE class of bolt.
11 TPI is .0909 inches, 2mm is .0787 inches, So 2 mm pitch is more close to a 13 TPI. And yeah better use a thread gauge or ? to check the threads before impacting them in.
Not only that SAE are stamped with dashes, not numbers. Metric bolts use numbers. at least that is the way I have seen it in my limited travels.
Absolutely 10000000%%%%% 5/8-11. I'm going to guess grade 8 will be fine. The service manual says to torque the bolts to 210 ft-lbs, which is conveniently the recommended torque for a dry grade 8 5/8-11 bolt, according to multiple charts I found online.
Interesting. Even though I have a fastener fetish, I did not realize some manufacturers make 12.9 equivalent, 5/8x11 SAE cap screws. They are definitely an oddball, and don’t exist under any ASTM spec I can locate. But, our friends in India and Pakistan can certainly hook a brother up. Bobcat Doosan must have got a good deal on some bolts 12 year old Jayesh at the bolt factory must have messed up on the heat treatment. He hasn’t been pulling his weight lately. Puberty is probably messing with his head.
210 ft lbs, Yeah no problemo, I worked on a 2004 murano some time back and I'm sure it took close to that much torque to loosen most of the I think 12 mm size bolts, never worked on something with such crazy tight small fasteners.