jigsaw or holesaw for 46mm hole in 6mm steel ?

[magnetman]

I have previously cut a lot of holes in steel usually using a jigsaw but I am just wondering if a hole this small (46mm) is manageable or will the blades tend to break as it is quite a small radius?

 

I favour the jigsaw as I have the blades but a decent holesaw will only be about £10 so if its a better option I will do that.

Today I cut a 175mm hole in 6mm steel with the jigsaw (for a porthole) so I am quite happy using that tool IF its appropriate.

 

Anyone tried smaller holes with the jigsaw?

 

Typos

Edited June 22, 2016 by magnetman

[Guest]

Think you will find it hard at 46mm. Have always used hole cutters at this sort of size.

[MtB]

Seconded. Decent quality hole cutter will do it beautifully and easily.

[Murflynn]

holesaw every time - lots of lubricant needed, ideally a 2 person job.

 

watch that it doesn't snatch your wrist - the drill must have a steadying handle.

[RLWP]

Hole saw. I rarely use lubricant with one, don't run it fast

 

Keep the saw as square to the job as you can

 

Richard

[Guest]

holesaw every time - lots of lubricant needed, ideally a 2 person job.

 

watch that it doesn't snatch your wrist - the drill must have a steadying handle.

All of that, and I always use a slow drill. Also drill a 6mm hole first with a mormal bit, rather than using the centre bit in the holesaw. The centre bit then just stops it from moving around. This stops the outer blade from slamming into the material (if the centre bit is used to drill guide hole.) I have spoiled a couple of holesaws by ignoring that method.

[magnetman]

 

 

I started off the first of 4 below-gunnel portholes with a 177mm (7 inch) holesaw on my makita 14.4 drill followed by jigsaw when the drill started to melt. Yes a holesaw can snatch a bit and gives the drill a hard time !!

 

 

A good idea to drill right through first before using the holesaw thanks for that tip.

 

So its definitely not a jigsaw job.

 

I will get a Bosch holesaw for it.

 

 

Thanks

[bizzard]

I started off the first of 4 below-gunnel portholes with a 177mm (7 inch) holesaw on my makita 14.4 drill followed by jigsaw when the drill started to melt. Yes a holesaw can snatch a bit and gives the drill a hard time !!

 

 

A good idea to drill right through first before using the holesaw thanks for that tip.

 

So its definitely not a jigsaw job.

 

I will get a Bosch holesaw for it.

 

 

Thanks

It might need an arbor as well.

Edited June 22, 2016 by bizzard

[NMEA]

It might need an arbor as well.

Indeed, but Bosch do offer the same saws as the power change ones with the standard arbour fittings. Personally I prefer the power change type but you do have to buy the special pilot drill bits for them.

[magnetman]

I have a Bosch arbour for my 177mm holesaw - the type with the sliding collar and the pins. Hopefully this will fit the 46mm holesaw as well.

[RLWP]

I have a Bosch arbour for my 177mm holesaw - the type with the sliding collar and the pins. Hopefully this will fit the 46mm holesaw as well.

Probably, you will have to check. The small ones use a different arbour, and I don't know what size they switch at

 

Richard

[Blazeaway]

WD40 is a good cutting fluid when using a hole saw. As others suggest keep the speed down and dont put pressure on it when starting the drill revolving.

[Guest]

WD40 is a good cutting fluid when using a hole saw. As others suggest keep the speed down and dont put pressure on it when starting the drill revolving.

We used WD40 often when in the electrical game. If all else failed, we used milk as somebody always had a drop of milk!

[adrianh]

A 46mm dia holesaw fits the 2 pin drive arbour. Always drill a seperate 6mm dia pilot hole. These arbours take a 1/4" dia short form stub drill that can break easily if the hole saw kicks of or jams.

Ideally you need a very slow drill around 250 - 300 RPM as these are a fairly course tooth profile.

I use an SDS chisel drill with a chuck adapter fitted and the hammer disabled ( mine is a Makita professional job as I do this as part of my job) - these can be hired .

These usually have a safety clutch on the chuck rotation drive so will not attempt to break your wrist if they jam - likely as the cutter exits the hole !

Always use the side handle and 2 hands on the drill, also a good quality oil or grease to lubricate the cutter frequently if you want it to last .

If you are drilling from the inside outwards over water, take care the whole lot does not drop into the water after going through the steel plate, having possibly worked loose in the chuck.

[RLWP]

Now, there's experience talking!

 

Richard

[NMEA]

I have a Bosch arbour for my 177mm holesaw - the type with the sliding collar and the pins. Hopefully this will fit the 46mm holesaw as well.

That's the standard arbour and it fits the Bosch power change 47mm if you remove the power change fitting from the saw, it will also fit the non power change Bosch saws so in either case all is good.

[Flyboy]

Mark out with dividers, chain drill & either file to size with a half round or rotary file.

[RLWP]

Mark out with dividers, chain drill & either file to size with a half round or rotary file.

 

You are very modern. You should chain drill, use a chisel to cut between the holes, then finish with a half round file

 

I have done that in the past - give me a hole saw any day

 

Richard

[magnetman]

Chain drilling might actually work for this job as I am installing a brass deck filler as a "skin fitting" which is going to be the (wet) exhaust outlet from a generator. This has a flange and 3 bolt holes to hold it in place so there is a little bit of leeway for the hole. Anyway I have ordered a Bosch holesaw so will use that.

 

Thanks for all the tips and suggestions

[ditchcrawler]

I like the Rocol cutting lubricants,

[MtB]

I like the Rocol cutting lubricants,

 

 

Me too. Water-soluable oil.

 

But copious WD40 is still a million times better than nothing!

[RLWP]

 

But copious WD40 is still a million times better than nothing!

 

In your experience. In mine, letting the swarf fall freely from the cutter is more beneficial

 

Each to their own

 

Richard

[magnetman]

I usually use CT90 cutting compound with the jigsaw but when I did the porthole yesterday (7 inch hole in 6mm steel) I couldn't find the pot so I went slowly without lube and changed the blade over when it got hot. I used 5 blades but they are all still usable for other jobs as none of them got too hot. It was fine with no lube on it - I was a bit surprised in a way.

[MtB]

 

In your experience. In mine, letting the swarf fall freely from the cutter is more beneficial

 

Each to their own

 

Richard

 

 

I remain to be convinced that any type of lubrication ever arrives at the very point the cutting edge is actually doing the cutting. Its main function is cooling. I agree a dry hole saw works perfectly well for as long as it takes for you (or more likely, me) to misjudge the temperature of the blade.

 

The instant it gets 'too hot' it loses its edge and ceases to work and I have just ruined a cutter. Using lubricant keeps the cutter cooler and makes such a misjudgement less likely in my experience.

[magnetman]

I remember years ago I was drilling some 16mm holes in 10mm steel engine beds. I bought a standard blacksmiths drill and the bloke at the shop said "do it slowly". I am impatient and tried to do it too fast. Needless to say I overheated the edge of the drill and having no bench grinder at the time I was not able to make a new edge so I bought a second drill bit - same advice "go slowly" I still tried to do it too fast. By the third bit I realised that doing it slowly (very slowly!!) Was in fact very effective same seems to happen with the jigsaw but I am still tempted to push it too fast !!