Milled Down Tool Holders

I'm of the opinion that unless you gain the use of an insert holder that otherwise may not have been available to you, there is no good reason to mill them down. Size of insert goes up with larger holders, so the potential cost is greater, but there's often no benefit in using larger inserts. The exception can be where one has a center distance that precludes using a reasonable sized holder, so milling makes it possible. My Graziano lathe, equipped with an OK Rubber Welders square indexing tool holder (by choice---I like that particular design) is an example. The largest tool that the machine will accommodate with that setup is only 1/2". Many of the 1/2" holders use a tiny insert, which are ill suited to the horsepower I have at my disposal (3 horse), so I have milled down a 5/8" holder for running negative rake TNMG-322 inserts. They're very popular and available reasonably priced. I gained something in the process. You may or may not, but if you have something going that makes it attractive, there's certainly no harm in doing so. Depending on the nature of the inserts in question, you may find that larger inserts may not offer the small tip radius that you desire. All depends on the inserts. Do your homework before investing.

Harold

Jim,

An excellent example of benefiting from the upgrade, to which I had alluded. There are times when small inserts just don't cut it (no pun intended) and modifying larger insert holders so avoid breakage is the order of the day.

Yours is a very impressive story.

Harold