Hi all, I am trying to drill 7/32 holes for pop rivets in 20 ball cap tops for fence post for our new wrought iron fence. Thye posts are 2"x2" 14 guage steel, the ball caps have a box bottom that fit over these post tops. The fencing came from fence-depot dot com and I assume all the parts came from China. I was originally was going to buy a cheap stick welder to attach the ball caps to the posts but realized I would probably make a mess out of the paint trying to get a good electrical connection for the welder, the extra heat would also screw up some of the paint. I decide I can drill and pop rivet these onto the fence posts much easier. SO, I go and buy a set of Dewalt bits with the titanium coating. I was able, with much effort, to drill a few holes before dulling out the bit. I had to apply excessive force with my drill press to get through the first millimeter or 2 then it went through relatively easily. I tried smaller pilot bits which also acted like i was trying to drill throug a lock or some other very hard (case hardened?)steel. I went back to Home depot and spent like $30 on a set of Rigid cobalt bits. They were no any more effective in getting through the harder outer layer of the cheap ball cap post tops.
I always used oil when I drill to preserve sharpness of my bits ... I am at a loss here... I have drilled though quite a few different material in my life.... i reminds me of trying to drill though hardened lock bodies. These post caps were only about $2 each, I am wondering if the sides of the box part of these ball caps I am trying to drill through came from tool steel scrap or ????? I have never had a problem like this before. any suggestions? I am thinking of going back to the welder idea...I am sure that welding will have it's own set of problems!