Jeff-C175 7,202 #26 Posted November 2, 2021 (edited) I found this chart... a little more straight forward than the Fastenal chart, no K factors or Ecoguard nonsense. I am presuming that those bolts are at least grade 5. Here's the head markings, no idea what "MF" means... well, actually I do but I won't repeat that here. I'm pretty sure it doesn't mean Massey Furgeson! I loosened them and then re-tightened them with a regular ratchet to what I felt was a good tightness then put the torque wrench on them and all four clicked at around 8 foot pounds, so my calibrated wrist is still in spec. I think I'm going to take them out once more and put some blue loctite on them. They do have serrated flanges so it's probably not neskissairy but I'm gonna do it anyway. Can't hurt! Edited November 2, 2021 by Jeff-C175 Share this post Link to post Share on other sites
Howie 886 #27 Posted November 3, 2021 That's the manufacturers ID on the head of that bolt. Has to be there so it can be traced for whatever reason! I would say that is probably a grade 2 bolt. Thats what I did for 45 1/2 years of my life. 1 Share this post Link to post Share on other sites
