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View Full Version : Endmill as a boring bar.



oxford
04-27-2013, 12:52 AM
I had to improvise today. I used an endmill in a bxa tool holder as a boring bar. I didn't have a boring bar small enough for the hole I needed so I used 1 flute of a 4 flute endmill as a boring bar. It worked surprisingly well. I did kick the compound a couple of degrees off zero so only the front tip of the endmill was cutting. I don't have my tail stock back together yet so I also used the endmill as a plunge drill in some delrin and then used it as a boring bar as well for a different project.


For a down and dirty boring bar it is a lot faster than grinding a hss blank as long as you don't have a great depth.

JRouche
04-27-2013, 01:22 AM
I had to improvise today. I used an endmill in a bxa tool holder as a boring bar. I didn't have a boring bar small enough for the hole I needed so I used 1 flute of a 4 flute endmill as a boring bar. It worked surprisingly well. I did kick the compound a couple of degrees off zero so only the front tip of the endmill was cutting. I don't have my tail stock back together yet so I also used the endmill as a plunge drill in some delrin and then used it as a boring bar as well for a different project.


For a down and dirty boring bar it is a lot faster than grinding a hss blank as long as you don't have a great depth.


YES! That is exactly how you do it! JR

Don Young
04-27-2013, 09:14 PM
One of my first lathe jobs was boring some 4"x4"x4" aluminum blocks bolted to the faceplate of a Craftsman 109 lathe. I used one lip of a 3/8" drill clamped in the lantern toolpost and turned to what looked like a good angle. Worked very well.

DATo
04-27-2013, 10:16 PM
Works well on a milling machine boring head as well. I have both the small and large Bridgeport milling heads and they will support the 3/8 and 5/8 dia. shanks of end mills respectively. When I have an end mill which has a shank of this diameter and it is too far gone to sharpen any further I use it as an indexable boring cutter. Got a four flute end mill? Then you have a four toothed indexable boring cutter. No need to be fancy just grind the bottom on a pedestal grinder and you are ready to go. Now I know someone out there is going to mention that there will be no side relief but to date this has never been a problem for me in attaining accurate sizes.