What causes the drill bit to break at the end of the hole?
When the speed is low, the feed is too large.If the cutting resistance is greater than the twist strength of the drill, the bit can be broken when the speed is low.
The cutting edge angle is not proper, and the iron chip blockage causes the resistance to increase.1) and the principle of uniform, when the edge angle is not appropriate, the drill operation must not only overcome the cutting resistance, but also overcome iron friction and pore wall blocking resistance, resistance and greater than two fold twist drill strength, also can cause the drill bit break.
Small bit not used high speed, with small feed amount.A small drill can withstand torque is small, the use of high speed with a small amount of feed, can reduce the small rotating cutting output, so as not to drill to bear large torque.
