Www American Machinist Com Content Site304 Articles 07 01 2007 68573 Prac Ideasg 00000044586
Www American Machinist Com Content Site304 Articles 07 01 2007 68573 Prac Ideasg 00000044586
Www American Machinist Com Content Site304 Articles 07 01 2007 68573 Prac Ideasg 00000044586
Www American Machinist Com Content Site304 Articles 07 01 2007 68573 Prac Ideasg 00000044586
Www American Machinist Com Content Site304 Articles 07 01 2007 68573 Prac Ideasg 00000044586

Tap A Stuck Bushing

July 10, 2007
I needed to pull a mild steel bushing out of a blind hole, but I could not get a hold of it to do so. Here's what I came up with to grip the bushing. Bushings usually have standard size I.D.s, and taps are 0.005-in. oversize on their major diameters for ...
I needed to pull a mild steel bushing out of a blind hole, but I could not get a hold of it to do so. Here's what I came up with to grip the bushing. Bushings usually have standard size I.D.s, and taps are 0.005-in. oversize on their major diameters for producing thread crest clearance in a tapped hole. With that said, my idea is to thread a nut onto the appropriate size tap for the particular bushing I.D. size. I then thread the tap into the bushing, and the crest of the threads bite into the bushing's I.D. walls for just enough grip to pull the bushing out using pry bars. The minor thread marks don't harm the bushing. I have found that fine-thread taps give the best hold. A washer also can be used under the nut to assist in prying out the bushing.

Mike Giaraffa
Maryland Heights, Mo.