# diamond needle files



## marcros (22 Aug 2014)

I need to make a scratch stock, so need some needle files (diamond or otherwise). Any recommendations?


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## Spindle (22 Aug 2014)

Hi

Dremel, (other brands available  ) and associated grinding wheels / discs.

My best needle files are Vallorbe but I wouldn't use them on HSS :shock: 

Regards Mick


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## marcros (22 Aug 2014)

thanks Mick. I will have a look at Dremel options, but I fear that they may be too aggressive in my hands.

My fear is the speed of removal- i have a small bead to produce that consists of a quarter circle of 1/8" radius convex (on the scratchstock "cutter"), with a flat either side. The cutter is going to look like the timber in this link, http://www.bunnings.com.au/porta-30-x-3 ... -_p0088230 but in miniature- the effect will obviously be the opposite. At least with a file, i figured that i would be able to do a very careful stroke at a time.


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## Spindle (22 Aug 2014)

Hi

Easily achievable using a Dremel with stones, an 1/8" cylindrical stone and a normal 'wheel' shaped one. Failing that several router bit manufacturers have bits for dolls house mouldings etc. which may suit if you are prepared to go mechanised.

Slip stone sets are available for that final touch prior to use.

Regards Mick


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## marcros (22 Aug 2014)

ok. i will take your word for it and look at the dremel.

I am not against to mechanised, but it is one of those little jobs that is probably quicker and easier by hand rather than setting up the router to do 4 feet of a moulding. I would like to see whether i like the profile first too- at least a scratch stock is essentially only labour. This one looks nice as a sketch, but i prefer to see it properly..


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## Inspector (23 Aug 2014)

Chain saw files come in several diameters and are not all that expensive. Perfect for what you need.

Pete


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## marcros (23 Aug 2014)

I want to make a convex shape on the metal not concave so I think that chainsaw files will be the opposite of what I need.


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## Inspector (23 Aug 2014)

Opps!  I thought you wanted to end up with a moulding that looked like the wood in the link. Well if you ever need to go the other way then the chainsaw files will work. :wink: 

Pete


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## Random Orbital Bob (23 Aug 2014)

marcros":9ubaioyx said:


> I need to make a scratch stock, so need some needle files (diamond or otherwise). Any recommendations?



This is worth a watch.


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## AndyT (24 Aug 2014)

I have a set of 4 branded by Trend which I use for that sort of thing. They cope well with jobs like tweaking the profile of moulding plane irons. For your scratchstock blade there's no need for very hard steel. You could use a bimetal hacksaw blade with the hardened teeth ground off.
It could also make sense to soften the steel by heating up to red and cooling slowly before you file the profile, then harden again afterwards.


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## Sheffield Tony (26 Aug 2014)

AndyT":239j8m6j said:


> For your scratchstock blade there's no need for very hard steel.



+1 - a blunt hardpoint handsaw is a good source of material, which will do for as much moulding as I'd willingly do by scratch stock, but will cut with an ordinary hacksaw and file. If you try the anneal/shape/harden route, you may be better making sure you can actually harden the material you want to use first. I have fallen foul of annealing what turned out to be M2 HSS, not so easily hardened again as carbon steel.


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## marcros (26 Aug 2014)

i have a blunt hardpoint saw that i was ear-marking from the job!


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## Eric The Viking (4 Sep 2014)

Well!

I was just about to post on needle files when I thought I'd have a quick look in 'ere first!

I have some really cheap ones from either Maplins or Toolstation - it's so long ago I can't remember which. You can also get them on eBay. They're quite invaluable.

Today, the reason for the posting, I 'as bin mainly rescuing worn out blades from my Bosch GOP multi-tool. It turns out they're blued steel, but NOT hardened (as far as I can tell). A triangular diamond needle file recut teeth in a completely worn out 'saw plate' pretty quickly. I should have done before and after pics really. 

I started with lumps on one end of the blade (used to be teeth), and just a worn smooth edge on the other end - teeth entirely worn away (note to self - don't use that type of blade for cutting through lath + plaster!). 

The result isn't brilliant, but it is functional, and for the 109-year-old in situ skirting board buchery I intend, will be fine.

I also had a go at one of the semicircular saw ones, not so badly worn, with really excellent results. It feels to the fingers to be sharper than it was new.

The issue with my diamond files is that, although they cut fast and last well, they're not very sharp-cornered, so the pitch of teeth I can do is very limited. I was going to ask if someone had sourced better quality ones, but it seems Andy T has done so. I'll look for the Trend ones.

They really are wonderfully useful little things.

I have to say though Marcros, the last time I made anything scratchstock-ish from hacksaw blades (actually a specialist contact extractor tool for the wiring loom connectors on our Seat people carrier), I ground the profile using the corner of my dry high-speed grinding wheel. A bit naughty but it worked a treat, especially as two prongs had to be ground as nearly identical as possible - could just clamp them and grind them as one piece.

E. (wandering off topic as usual)


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## bugbear (4 Sep 2014)

Sheffield Tony":1pnkq5jf said:


> +1 - a blunt hardpoint handsaw is a good source of material, which will do for as much moulding as I'd willingly do by scratch stock, but will cut with an ordinary hacksaw and file.



The traditional (and obvious) source for scratchstock material was old handsaws, long before hardpoint.

These work well (so obviously hard enough) and are (obviously) workable with a normal file, which is how saws are (were!) sharpened.

I'd expect the main body of a hardpoint saw to be softer than a old handsaw, since only the teeth are hardened (anyone know for certain?).

BugBear


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## Phil Pascoe (4 Sep 2014)

+1 I've thought about this - the steel in a throw away saw can be any manner of (rap because it's not actually used for anything - it's only a vehicle for the teeth.


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## bugbear (5 Sep 2014)

phil.p":xy9lviqa said:


> +1 I've thought about this - the steel in a throw away saw can be any manner of (rap because it's not actually used for anything - it's only a vehicle for the teeth.



Not fully true - it has to be _hardenable_ (and so must have some carbon) for the teeth to be done. I would expect the body to be in a close to annealed state though, and the steel to be the cheapest possible hardenable type.

BugBear


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## Eric The Viking (5 Sep 2014)

It can't be all that soft, as they're usually not that easy to kink, compared to older cheap saws. That may just be an overall improvement in steel quality though.


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## Phil Pascoe (5 Sep 2014)

Yes, of course. The teeth still have to be hardened.


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## Sheffield Tony (5 Sep 2014)

It is surprisingly hard to find out by Google any evidence on this one. One thing I did find was this thread:

scrap-hardpoint-saws-t55086.html

Which seems to fit with what I have found; I have used old hardpoint saw steel to make various scrapers, scratch stocks and even a bowsaw blade, which seem to keep an edge just like any other scraper or non-hardpoint saw might.

As I understand it, traditional (i.e., non hardpoint) saws are made from a not terribly hard carbon spring steel, supplied to the sawmaker pre hardened and tempered. It has to be soft enough to be re-sharpenable. Hardpoint saws I presume start out as a similar steel, but have the teeth induction hardened to be much harder than the rest of the blade, so the right flexibility is retained but the teeth can be much harder.


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