What is the tool to use?

For that range of sizes I'd go for a holesaw. You'd probably need a couple of arbors to cope with the range of holesaws you'd need - though not having used them on sheet brass I don't know how accurate the holes would end up.

Bosch do a wide range of sizes.

Regards,

In message , Stephen Howard writes

Beware of cheap holes sets available from DIY stores, they are intended for wood, plasterboard, etc.

If your requirement is to get a high standard accuracy and true circles you may have to resort to a boring tool in a lathe or milling machine.

Absolutely! The Bosch ones are very different from the cheap steel DIY ones with the split rings ( usually sold as a set, all sitting on the arbor ).

My father used to have a set of manual hole saws - these came complete with a die that you fixed beneath the work after you'd drilled a pilot hole. The substantial cutter was then fitted to the die through the hole and then the whole lot was turned by a lever attached to the cutter. Every few turns you adjusted a nut to drive the cutter into the work. Made lovely neat holes!

Regards,

Thanks. Hole saw was what I had in mind, but did not know they were called hole saws.:c)

Great accuracy is not required. I'lll get good quality individual saws, not those cheap multiple hole saw arrangements you see in DIY stores.

If the sheet will swing on the lathe, I usually stick it to a faceplate with industrial grade mirror pad/double-sided adhesive foam strip and trepan it. This works without problems for 1 mm aluminium sheet and is no problem for anything thicker.

If finish and tolerance aren't critical, why not use a flycutter?

On Fri, 01 Oct 2004 00:46:08 +0100, Stephen Howard

RS components stock round punches. Also rectangular and Dee Connector shapes for electronics cases. Whistons used to have them.

Search

for "hole cutter" or punch:

to cut 16swg mild steel.

Bill Derby

ps Was there someone on this list working at Loughborough University. Am starting a part-time course there next week.

Ah Whistons, that brings back memories.

I wish I had kept my copies of the 'cat' from the 50s. I still have items I bought from them that I have not used yet! (they will come in useful one day, honest)

Ian Phillips

Claims to cut 16swg mild steel.

Heavy duty hole punches will also do (Radio Spares # 363-0446). But they are expensive and need an hydraulic driver (Radio Spares # 363-0632).

I'll just use the hole saws with a bench drill or regular hand drill.

Regarding cheap hole-saws....

I was pleasantly suprised when I tried to drill a hole in mild steel with a v. cheap set from Axminster power tools - no brand name on box, about a dozen for 10 to 20 quid or whatever it was. Worked fine. I don't suppose it would stay sharp if I used them much, but OK for occasional use - which is not the case with many cheap tools which are merely useless.

This may or may not be accurate enough for the original poster, but good enough for what I wanted.

Hywel

I recently bought a cheap set by Hilka (£3.50 in Trowbridge Shires downstairs market, 8 saws and 2 arbors), and have used it with success on

10+ mm ali, various plastics and woods. In a bench drill, I removed the silly drill bit centering thing. Not tried it on steel, but I think it would cope for a few cuts before needing sharpening.

It's also the right sizes for model rocketry, if anyone else cares.

I think the difference is whether the saw part is wholly round and entire, or thin springy steel bent not quite in a whole circle round and fitting in a groove on a backplate with lots of grooves. If it's wholly round with a back surface all in one piece (except for needing an arbor) I'd guess it will be okay for at least light use on 'most anything.

Can I add a "Bloody hell" to the Deltic model thread too please. Impressive. I can't think of anything else to say!!

Cutting metal :) (you get the best of my love ... )