So I used my bulldog to 1-7/8 core drill through my brick n block wall for my 1.5" pvc discharge. Worked great.

However, now I can't get the core bit unthreaded from the spindle... This is embarrassing! This is a Bosch spindle with the permantely attached pilot bit.

I grabbed the area designed to take a wrench with a crescent wrench, but I'm not strong enough to hold the bit firmly enough with my left hand while I wrench the spindle with my right.

What's the trick?

This is how I loosen mine: hold drill vertical, bit up. While pulling down on shaft, run drill in hammer mode. A few percussion strikes is normally all it takes to loosen the bit.

I have taken them off using a rubber strap wrench to hold the core bit body.

Tried running it in hammer mode, still no luck.

Tried grabbing the body with channellocks, nope. Don't have a rubber band wrench.

Hit it with PB break free, did both the above, didn't budge.

Anything else I should try before hitting the gym?

Place the back third of the bit in a vise. Thread the shaft out with a pipe wrench.

I have a couple of hole saws with a long threaded shank. To remove the core that is inside the saw (and to unscrew the shank) the instructions said to tilt the hole saw in the hole that was cut to put it in a bind. Then reverse the electric drill to to back out the shank and eject the plug. Maybe worth a try and even use hammer mode if necessary.

pipe wrench on core at 'back side' of bit near shank drive

adjustable on 'stem'


grunt


all done

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Pipe wrenches are what I use on all my core bits, up to 4 1/2".

It's only embarassing if your wife takes it out of your hands and takes it apart.

Yes! Grabbing it with the channel locks down low worked. I assume u guys are talking about Stetsons when you use pipe wrenches but I don't have one that big. So yeah I just had to man up.