What grade of bolt

[Flat 10]

I have a machine where nuts and bolts are fitted through a clevis and another part of the machine IFSWIM. There is movement there and the bolts are getting well worn and need replacing. Should I used 8.8s or go harder with 10.9s? Will this just make the holes oval?

 

[tinman]

it would depend on what machine it is, what is being asked of the bolt, how often you need to replace the 8.8 and how hard the clevis is if one was to take all into account.

 

[clbarclay]

The holes will probably wear a bit in time anyway. Could you drill out the holes without weakening it and bush them?

 

[ACEngineering]

Is an imperial bolt slightly larger? Might take out some slop.

Were ever theres movement your going to get wear regardless imo.

 

[Bloders]

if you use 10.9., you can tighten them to a higher torque figure which will reduce movement in the joint.
Make sure you tighten them up as tight as possible.

 

[MickMoor]

The figures are indicators of tensile strength, and have no relation to wear resistance. The higher strength bolts are slightly more brittle than those with a lower figure. Bolt science is just that, a science, and my knowledge is very limited.