[hdwarner]

here are some proven tips from me on longevity of twist drills

When you purchase a brand new drill take an Arkansaw stone or some light sand paper and gently stone the face of the drill or the lip when these drills are ground new they have microscopic slivers that tear into large imperfections when drilling.

Try if possible to drill into another piece of steel when drilling through a piece { NO NOT INTO YOUR DRILL PRESS TABLE OR YOUR VISE } and don't completely drill through that piece either.

One of the most detrimental things that happens to a drill is when you drill through is that little thin section right before the drill breaks through gets so hot it anneals the hardened drill , were blacksmiths we know that right.

Be sure you have the correct speed for drilling , a slower speed is always better than a higher speed, if you have doubts.

Keep good pressure on drill ,

Another dulling factor is a drill that dwells

If you are using cutting oils this even worsens the dulling process. If you are not pushing the drill, think of the honing process, that is what you are doing honig the cutting edge away. A couple drops of oil is all that is needed at entry.

A properly dressed twist drill in a blacksmith shop, for what blacksmiths usually cut, will never need replacing just minor touchups. i have dressed drills on the job and drilled thousands of holes in mild steel with out any maintenance .

if there is any interest in this subject i will expand