Back saw for cutting steel and brass?

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If you want a flat bottomed slot, change files to finish off.

MichaelG.

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As per Brian’s link ... These are the ARC ones [which have ‘half round’ edges]

Edited By Michael Gilligan on 27/11/2019 14:23:23

Ah, that makes sense now, thanks

Ian P

When multiple heads come next to each other in a row I use a slitting saw to make the slots, it is a much neater sight when they are identical. With only one screw head a piercing saw with the correct blade thickness will do fine. If the head becomes very small when the thread is below M 1.0 a piercing saw with the smallest thickness of blade is best to use. A screw-head file is much too wide that work. Niko.

Hello all, interesting question.

First observation is that you'll never get a pretty slot using a saw with set on it. So using hacksaw blades whether they're wavy set or a normal wood saw with side set ain't going to cut it, if you'll excuse the pun.

The slotting file is the right tool, and I seem to remember correspondence from Ketan a few months ago saying he'd bought some - inadvertently - and were they of interest. Might be worth a call. A slotting file is a thin file with no teeth on the faces, but teeth on the edges so it cuts sideways - or downwards if you hold it on edge.

A razor saw has also been mentioned - that's what the top saw in this pic' is:

xxx

That's an Exacto razor saw, and it will cut brass but the blades aren't very hard and you'll lose the teeth pretty quickly. It's really intended for cutting wood, particularly balsa or similar.

The bottom one is a jeweller's backsaw - if you can find a source of good quality blades it'll cut anything a hacksaw would, as it's designed for cutting 9 ct gold which is pretty hard. The blades are removable from the brass back, and usually double sided, but beware of cheap and nasty blades they won't last as well as the razor saw. My Dad was a silversmith, we used to have periodic expeditions shopping for this sort of stuff round the Hockley Hill area of Birmingham, but I've lost touch with this over the last thirty years and I don't know where to buy these blades. I remember the good blades were expensive, but the cheap ones were absolutely useless!

The backsaw willl give you a good groove to guide the slotting file and remove the majority of the metal, but the blade on this one is only 0.35 mm thick so you need parallel cuts or follow with a narrow file to get a slot which looks in proportion. You used to be able to buy blades of different thicknesses.

HTH Simon

Edit - MichaelG has - as oft before - pipped me to the post about ARC's slotting files.

Edited By Simon Williams 3 on 27/11/2019 14:36:30

How did you manage to get 7mm square from 6.35mm round?

The ones I linked to were "joint square edge" Michael, as I assumed that the slots should have a flat bottom.

Brian G

EDIT:  Sorry Michael I finally grasped what you meant, follow the saw with a slotting or round edge file then finish off with the square one.

Edited By Brian G on 27/11/2019 17:44:13

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My apologies, Brian ... The ones that I bought from ARC, and photographed, were ‘joint round edge’

**LINK**

https://www.arceurotrade.co.uk/catalogue/results.aspx?search=joint+round+edge

MichaelG.

model making saw blades that fit in knife handles will cut brass, mine have 42tpi.

I use modified 32 tpi hacksaw blades in a pad saw handle, I have used this method for many years and it works well. I use part blades and grind the teeth flat on each side first on a surface grinder then grind equal amounts of either side to the thickness I want. I find 0.010 ; 0.015" & 0.020" cover most things but now and then use one with just the "set" removed thus the standard blade thickness.

Here are a couple of photos I took tonight--more in my albums

John

Would these little saws be of any use, page 5 in the catalogue.

http://www.morgancarbon.com/pl/files/morgancarbon-pl/martindale-motor-repair-hand-tools.pdf

Dennis

That’s a handy looking design, Dennis

But I do wonder [as with many of the commercial saws] what materials it will successfully cut.

Nigel mentioned screws for clocks, so one might reasonably assume that at least some of these will be steel.

MichaelG.

Lee Valley Tools sells Gent's Saws if it helps

Thomas Flinn in Sheffield England still make Gents Saws. They are wood workers tools in the main but might be worth trying. **LINK**

For wood work they are very useful tools I have found.

Allen