Making steel control arm bushings inserts

[FarmerSid]

Hey all! Wanted to run something by you all and get some opinions. I'm thinking of buying new control arm bushings, removing the steel insert, drilling the polyurethane out to the OD of a new larger steel insert and inserting the new steel insert inside the polyurethane bushing.

Are these steel inserts hardened?

The factory bolts bolts are metric and a 10.9 hardness. I'm under the impression that either the bolt or bushing needs to be hardened but not both. Am I correct in that thinking?

The purpose of this is to increase the bolt size that holds the control arm on from 12mm to 16mm.

 

[rsanter]

The bushings are not hardened as the point is to get a clamping force from the flanges on then and that they will not rotate. The poly bushing it to rotate on the steel bushing

Bob

 

[APEowner]

If you've got an application where you need to increase the control arm bolt size for strength then you probably aught to be looking at something other than polyurethane for the bushings. Also, it's not easy to drill polyurethane with any precision.

I'd be looking at either a delrin bushing (that's what I made for my big block, road race Camaro) or if it's strictly a track car steel bushings

 

[FarmerSid]

Vehicle is just a daily driver. Want to take a replacement set of bushings that come with new steel sleeves, and install new steel sleeves that accept the larger M16 bolt. Just wondering what the steel is that is in the bushing kit. Thanks for the explanation rsanter.