Outer Limits 4x4 Board

i have to cut and weld a 19mm masonary drill bit. (to shorten it)

its a proper ramset bit so some sort of hss i would imagine

i have to cut through the flutes and rejoin there as the shank is tappered down for the sds-plus slots to go in the drill

i figured to make sure its very clean(its a used bit) pre heat - weld - and mabe put in the oven to cool.

i have a boc 250 mig with normal wire and argosheild or stainless wire and straight argon both 0.9mm wire

cheers, serg

hey mate I have done heaps and never had one fail. I normally lengthen them however. I would use mild steel wire, gas etc... I have used angle iron to align them and is always works quite well. I crank the welder up high and weld using a series of tacks on opposite sides like bolting up a set of wheels.

I think pre heating would cause more harm than good. perhaps a little heat over the weld area after but i have never bothered. It is very easy to see if the drill in not centric so don't worry too much. I don't think masonry drills are nearly as hard a steel drills as the tip is the only area doing the work.

cheers bru

cheers mate,

it came up pretty good. the sparks indicated that it was made from something half decent. once i had the tip and chuck end cut it was just a mater of lining up the flutes. the root dia would have been about 12mm so i ground back the edges 45 degress both sides to get good penetration.

runs pretty true. was a bit harder to line up as the tip end was only 60mm long and the chuck end only one full flute then reduced shank.

will find out on tuesday when i'm drilling 40mpa tilt panels to insert a coil tang.

cheers serg

if you quenched the drill after welding it will be more likely to crack in the heat affected zone but should be fine if you didnt

AdrianGQ wrote:if you quenched the drill after welding it will be more likely to crack in the heat affected zone but should be fine if you didnt

Quenching makes steel harder, harder steel can be more brittle though.

thats what he was saying