Even though the drill bit will work in hand drills, we do not recommend using hand drills because of their slower speeds which reduces the cutting action of the bits. Truebite cutting bits were designed to be run at high speeds of 28,000 rpms. The standard pistol grip hand tool runs at only 1300 rpms. At slower speeds you are more apt to put pressure on the bit to make it work faster which can cause bit breakage. If after following the instructions, you have chatter and broken bits, your Dremel may have a bad collet or dust under the collet .
Dust cause the bit to run uneven and results in chatter, chipping and possible breakage.
If another motor tool is not available to test the bit, replace the collet in your Dremel. Inc. All rights reserved.