Thread: What drill for bi-metal hole saws?

I have recently bought a bi-metal holesaw kit for a job I'm working on, and thought I would run it with my Metabo SBE 1100 Plus. This drill was given a go as It has a 2 speed box, and can be preselected for a range of speeds- couldn't hurt, I thought, as the bit I was using needed about 300RPM. I usually only use this drill for masonry drilling, where it works great, but I'm new to using hole saws.


The drill was performing great, but kept going into overload, where it cuts to a low power output. A bit annoying.
My other corded drill worked fine, but the cordless didn't have the beans to make the magic happen.

Wondering what drills you blokes (and gals) are using for hole saws? The project I'm working on will need a number of holes up to 50mm in 6mm mild steel plate.
I'm gathering evidence for a new tool acquisition, to be presented to the minister of war and finance.

Most of the holes I’ve drilled with hole saws have been with a 1.5HP DP but the odd occasion where I could not get the work piece under the DP I have used my $69 Ozito demolition drill in drill - no hammer mode. One issue with it is if it catches it will spin you around and injuries may eventuate. On one occasion I sprained my wrist. BTW 300 rpm is probably still too fast for a 500 hole, I’d be looking at more like 100 - 200 rpm. Also I’d be using lots of coolant/lube.

In a drill press or mill I would be thinking 200 RPM for a 50mm hole saw in mild steel.

By hand I'd be at 100 RPM to provide more reaction/trigger release time for when it catches. Or have a full time assistant with their hand on the wall switch.

Plenty of lube in both cases.

Should mention, 300RPM was for a 29mm dia hole in the same material I originally mentioned- the closest I could get to the 260 ish RPM Sutton Tools recommended for that particular bit. It was drilled without the hammer action (I'm daft, but not that daft).

I wish I had the luxury of a drill press for this job... but space to store it, and the use it'd get outside of this job is questionable.

I would rent a magnetic drill if I had a number to do.

Pete

Hi Guys,

There is no way that I would use a hole saw in a hand held drill. I've used hole saws up to 6" inch in the drill press. The only other time I can recall was cutting holes in the plasterboard ceiling with a hole saw using it in a brace.

The metabo at least has a torque limiting clutch. They make good gear.
Same technology in the SBE 1100 Plus,
As well as the BE75-16 which I also have.

Disregard the grinder in the video, this is just a convenient way to demonstrate the tech in their machines.

I used to have to do a lot of hole sawing at a place I worked, mainly used 40mm, 50mm, 75mm, 100mm but sometimes went up to 150mm. Never used electric drills, always low speed pneumatic, they don't try and rip your hand off when they grab.

I recently had a job where I had to drill 6 x 50mm holes in a 6mm stainless access plate on a tank - I have two holesaw sets, Frost and Lenox, the former has less aggressive teeth, so I used it with an Ozito brushless battery drill in low gear, and lots of cutting fluid. The battery drill has the typical adjustable clutch, so a bit safer than a mains drill.

I've done a reasonable amount of holesaw work in both Aluminium and steel. To be honest, a holesaw in steel is rarely the ideal solution, but they can work acceptably well. First off I would drill two to four holes around the inscribed circle made by the holesaw in order to allow the chips from cutting to fall clear and improve the efficiency of the cutting action, secondly I would use a lube such as trefolex (yes I know it says for hand tools only and it stinks when it gets hot, but it works), third I would not worry too much about speed if you are using a hand drill. As you have found out with your Metabo, dropping the speed lessens the cooling of the motor and the power output, so overloading and heat build up is the killer. Maybe a Mag Drill would be an option, but if I had a Mag Drill, I wouldn't be using a 50mm holesaw, I'd use a 50mm rotabroach (annular cutter). Holesaw life will not be good at increased speed, but holesaw life using a hand drill is compromised anyway. My Hilti battery drill would be ideal - 350 RPM and buckets of torque in bottom gear.

Just in case this is not clear,

Originally Posted by Karl Robbers

I've done a reasonable amount of holesaw work in both Aluminium and steel. To be honest, a holesaw in steel is rarely the ideal solution, but they can work acceptably well. First off I would drill two to four holes around and just touching the INSIDE of the inscribed circle made by the holesaw in order to allow the chips from cutting to fall clear and improve the efficiency of the cutting action, .

or OUTSIDE if the inside the circle is what you are after. This method also works really well in wood.

Great tips with drilling the holes. I did notice the swarf was building up, and I was picking it out with the magnet on the end of my scribe every so often. I'll keep that one in the memory bank for later.

I drilled most of the 20 holes in my project over the weekend with the BE75-16 corded metabo, whcih is good for 75Nm I've since found out. The Sutton tools cobablt bimetal bits have held up well, but I've found the weak link is the arbor adapter for the smaller sizes likes to chew itself out after about 10 holes. A trip to bunnings and 11 clams over the counter, and I was back in action.

Originally Posted by Commander_Keen

I've found the weak link is the arbour adapter for the smaller sizes likes to chew itself out after about 10 holes.

The trick there is to keep the cutter tight on the arbour ! If it starts to come loose then yes it will chew itself up.

I've cut a 115mm hole using a hole saw in a hand held drill.

It was in the front guard of the then 2 day old toyota prado to fit a snorkel. The kit came with a template so figured I'd give it a go. Had a bourbon first to steady my nerves!

The guard at that spot had several curves and so the cutter broke though at different spots at different times. Slow and steady with lots of coolant was the go.

Simon

Sent from my SM-G970F using Tapatalk

Originally Posted by BaronJ

The trick there is to keep the cutter tight on the arbour ! If it starts to come loose then yes it will chew itself up.

I worked that out in due course. That killed 1 of them.
The smaller diameter saws have a cheese-metal adapter which works with the arbor. I chewed the other one out at this point (between the blue and silver pieces shown in kit), despite being tightened right up.

The annoying part is that the arbor proper has 2 locking pins... which don't fit the holes when fully seated. So having it seated 'as intended' killed one, and having it tight killed the other!

If I were the apprentice, I'd be sacked. It's hard to find good help in my shed some days.