I have been drilling 5/16" holes in 4130 steel tube (1/16" wall) for many years with HSS bits and a Harbor Freight drill press set at 920 RPM. There has been occasional binding, but nothing to problematic. Now, however, even brand new bits are binding when it punches through every time. I've tried cutting oil, and other speeds (though I'm open to speed suggestions). I cannot figure out what is suddenly different about my setup/technique that is causing the binding. I feed slowly (but not too slow), and back out to clear debris (though I didn't need to back out in the past). The belts aren't slipping. I've also tried a new parabolic bit without success, as well as a few different bit coatings.
I'm open to anything, including buying a nicer drill press (though the Harbor Freight drill press has been a workhorse for many years). This is a big part of my livelihood and I do have a self-imposed deadline (creating new stock before I run out of old stock). I'm at wits end and much appreciate any ideas. Thanks!
I'm open to anything, including buying a nicer drill press (though the Harbor Freight drill press has been a workhorse for many years). This is a big part of my livelihood and I do have a self-imposed deadline (creating new stock before I run out of old stock). I'm at wits end and much appreciate any ideas. Thanks!
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