Unless the set screws have been replaced it is probably brass. So it won't take much to booger it up. When you get it out use lots of Fel-pro antiseize on the new one and maybe next time it will come out.

They are SS. I have replacements in SS and regular steel. I was planning to use anti-seize. I would just buy a new hub/rotor but worried about matching. Brake caliber fine so I don't need to buy the whole assembly. Trailer has Buddy brakes and I think a UFP hub will work.

The rotors are DB35s and found them on several sites. I had to fix the left side tire and the set screw on that axle is seized also. During deer season I am going to get back to work on them. I am not opposed to buying new hubs and rotors but worried about getting the caliber bolts out. Adding calibers would double the cost.

Since the set screw is stainless steel you will need to run the drill bit way slower than you would on carbon steel or it will work harden very quickly. Keep cutting oil on it will also help. I think the heat rout would still be the best option. Good luck either way.

Are we still messing with this?

Kinda, I had a flat on the other side so I have it soaking in PB Blaster now. I am going to wait until deer season to get serious about it. Cooler weather and using boat less so it can sit on Jack stands for a while if it needs to.

If you use heat why would you heat the screw or bolt that you are trying to extract ? By doing that you are causing the bolt to expend inside the hole, by heating around the bolt and using a penetrating oil we use corrosion x in the aircraft field it will wick around the bolt.With the heated area it will draw the pen. oil around the threads Then try to loosin if it moves don't force it- tighten it and add a little heat and re -wick the threads again it will come out.

It will actually help to heat the screw and surrounding area if you let it cool between cycles. The expansion/contraction will break the seized parts loose. Then, after a few cycles, heat the surrounding area just enough to make it expand and hopefully you can get that rascal out of there.

Heating the steel pipe plug is the best method because it will cool quicker than the cast iron hub, shrinking quicker, alowing the plug to be removed. Done for years removing oil galley plugs on motors.