by Roger Stromberg

Marking Drills

When I was still working at Navistar, I maintained an electronic deburring machine for deburring connecting rods. This operation is, for want of a better description, a reverse chrome-plating system. If you are chrome-plating parts, the plating builds up faster on the sharp edges than on the flats.

If you reverse the current flow and use a salt (we used sodium nitrate) solution, the process is reversed and the sharp edges are eroded away.

This process works well, but the fixtures, being brass, also get eaten away. That meant I was constantly making brass fixture parts. I was using 6-32, 8-32, and 10-32 taps along with the requisite tap and clearance drills. The lighting was poor and my eyes are old, so to differentiate one small drill bit from another, I used a paint pen and marked the tap and the clearance and tap drill each with one color and so on for the rest of the drills and taps, each with their own colors. The drills can be returned to your drill index and you can immediately pick out the one needed without resorting to a magnifying glass.

Thanks, Roger, your subscription has been extended by an issue!

Click Here to Sign Up for Pass Along Email Tips