They're aluminum, and just like a rivet, can be drilled out w/ a (smaller then 1/4").
YES, drive the pin flush. One end of the tool is dished, just to help center it until the pin is started into the counter bore. I'm finishing up some directions right now. The first run went out w/o any, simply because you guys had waited a while, and I wanted to get parts in your hand ASAP.http://www.mcmastercarr.co
sells the anchors. Or better yet, contact me and I'll send you some so you don't have to order.
Aluminum Dome Pin-Drive Anchor W/Aluminum Pin W/Aluminum Pin, 1/4" Diameter, 25/32" Length
In stock at $6.69 per Pack
This product is sold in Packs of 25