Depending on the depth of the holes, it may take two setscrews to completely fill them. My current props take two setscrews of differing lengths to fill to the top. On the first screw, I apply some Super Lube on the threads, in order to make sure I’ll be able to get them out. On the outer screw, apply a good coating of TeffGel to the threads for anti-seizing and sealing purposes. Grainger.com is an excellent source for setscrews of all shapes, sizes and thread. I also keep the appropriate-size tap for the bolt hole, along with my puller, just in case.