When drilling metals, excess heat is avoided by staying below a recommended linear cutting speed.?
Yes, and you may cool the cutter with water or slurry.
Maybe it's just me
I avoid excess heat with proper bit for the material being cut, bit being in sharp condition. of course run it at the right speed. v=r x omega just get your angular velocity in radians/sec
THIS IS NOT A QUESTION .
While cutting a metal rod, the abrasive surface wears away while cutting the metal. There is a shower of sparks and the metals burns away without a problem. While drilling metal, the heat generated is not high enough to cause any worries. If there is a problem of heating, then precautions are taken. These drill bits are made of HSS steel with 5% cobalt, and is cooled while drilling using special drilling oil.