32mm hole in 3mm mild steel

[bigegg]

I drill holes that size in 3mm steel regularly with a Christmas tree drill. - think I bought them from Aldi or Lidl.
Start with a 3mm pilot hole.

Only paid a pound for a pack of 3, so I cleared the shelf - think I got 10 packs
They last a fair few holes, run slow with spray lube (from Screwfix).

 

[smashweld]

what's the gen on this type of holesaw?

https://www.amazon.co.uk/Starrett-SM31-Metal-Stainless-Steel/dp/B00C3ISDGK

I've definitely never used one of those before....watched a Youtube vid comparing this type, the usual holesaw and the anular mag drill type...this type was the worst by far, didn't even get through the 1/4" plate test piece....what advantages does it have?

 

[anto44]

what's the gen on this type of holesaw?

https://www.amazon.co.uk/Starrett-SM31-Metal-Stainless-Steel/dp/B00C3ISDGK

I've definitely never used one of those before....watched a Youtube vid comparing this type, the usual holesaw and the anular mag drill type...this type was the worst by far, didn't even get through the 1/4" plate test piece....what advantages does it have?

I bought a Chinese version of one of these and it's actually pretty good. Done a good few holes in mild with it and even one through 10mm stainless and it's still sharp.

 

[brightspark]

at the right speed and feed using cutting oil it should be pretty good and more rigid than the hole saws with a seperate arbour .starret are one of the best. should outlast the hss ones by a good margin

 

[smashweld]

Says 2mm recommended cutting depth for the 32mm version ...think I'll give it a try

Also...had kinda written off the idea as thought it was too small but have a rotabest mag drill...turns out the biggest size it takes is 32mm! Pillar drill would be better tho

 

[timgunn1962]

There are other manufacturers Carbide-tipped all-in-one holesaws available pretty cheaply. The ones I have tried have all worked well. I'd certainly be interested to see the specific youtube vid that found the Starret TCT version performed poorly because that feels unlikely to me in an unbiased test. TBH though, it's difficult to imagine any fair comparison of a Rotabroach with a holesaw anyway.

The one-piece TCT holesaws seem to be more precise than the HSS holesaws that use a threaded arbor. A lot of electricians use them for drilling gland plates because there's less cleanup and filing to do.

The ebay ones from the far East are cheap and effective but no good if you need one in a hurry. RS sell pretty good ones under the RS Pro brand with the 32mm just under ten quid plus vat. It's certainly worth shopping around.

I used the RS Pro 32mm to make/remake some holes in 2mm wall, 200mm dia stainless pipe. They were too big to get under the bench drill and the mag drill wouldn't stick to the stainless pipe, so I had to use a handheld drill. I'd previously cut 22mm holes with a holesaw and needed them 32mm instead, so didn't have anything for the pilot drill to guide into. I cut a hole in a bit of 6mm scrap plate, clamped it to the outside of the pipe over the existing 22mm hole and used that to guide the 32mm holesaw. I had 8 to do and managed all 8, plus the guide hole in the 6mm stainless scrap, on a single holesaw.

They are only recommended for flat surfaces and it coped surprisingly well with the interrupted cut as it broke through on the pipe. I suspect it would have struggled on a smaller diameter pipe though.

 

[anto44]

They are only recommended for flat surfaces and it coped surprisingly well with the interrupted cut as it broke through on the pipe. I suspect it would have struggled on a smaller diameter pipe

I've drilled a good bit of stainless pipe and I've taken the teeth off a few cutters when they first break through. If you don't ease off quick enough as it breaks through you bit is toast.

 

[smashweld]

...I bought the starred SM 32 holesaw....fine for steel but clogs up almost instantly on aluminium. Surprised they have a separate arbor too as looks,like a single piece in the photos.
Also I **Language**ed up slightly...didn’t notice the collar on it...I wanted to go right through some 3mm 40*40 box from one side so ended up using an old 30mm regular holesaw I had and the burr
I think these ‘CTD’ models are one piece and no shoulder...prob should have got that!
https://www.amazon.co.uk/Starrett-CTD32-Cutting-Carbide-Tipped/dp/B01E0ABPIG

Hers the comparison vid I saw...

 

[normspanners]

If they need to be accurate a normal two flute drill will not cut it very accurately IMO, why nut use a hole punch they are quite cheap.