Making holes in dovetail saw blade for handle, high carbon alloy

[the great waldo]

All you need to do is clamp 2 pieces of hardwood on both sides of the saw and drill through the wood and saw blade, obvoiusly a good quality hss drill ( a cobalt drill would most likely work) the 2 pieces of wood will support the drill and stop the drill pulling when cutting through thin metal. I made up a jig to drill 8 mm holes in soft brass 0.4mm thick 12mm wide strip, when I had to make 50 square washers to raise the carbide inserts on my spiral planer head (the company had not machined the cutter block right for my planer and it was too much hassle to send it back over the pond. The first try at just using the drill press and as expected it just snatched the brass and tore it up. I made a little jig with maple and clear perspex to hold the brass strips on both sides and drilled through all 50 in no time. I would recommend a drill press as you can control the pressure of the drill. At a pinch you could also use a dremel with a tapered grind stone , and if your'e worried about losing the temper just make a little moat with blu tack or plastacine and use some suitable lubricant.

Cheers
Andrew

 

[IWW]

Try cobat drills cuts through SS sheet better than hss.

I forgot about these. They will do better than ordinary HSS bits, but you will still only get a few holes out of them in saw plate if my own experience is anything to go by (the bits I tried may not have been 'Best British Quality'). The OP just wants two holes in a single saw with the least fuss & honestly, a new HSS bit will do that as long as it's of decent quality & if you sharpen it up again afterwards, you are well ahead.
If you want to make several saws then it is certainly worthwhile investigating alternatives. Carbide bits will give far better service, & if you get really serious, those punches look like the bee's knees....
Cheers,

 

[IWW]

Andrew posted while I was typing. If you are nervous about drilling your plate bare, sandwiching it will certainly prevent any catching and having your saw blade turn into a ninja weapon, but it is highly unlikely to catch using a regular drill, they don't self-feed in steel like they do in brass. Drilling brass should always be done with the workpiece well-secured! (I've ignored that advice more than once with unpleasant results). Using the sandwich technique will increase the difficulty of placing your holes accurately by a factor of 10. You can simply drill the holes in situ, but you may get enough flare on the exit side to lock the plate in the handle if it's a reasonable tight slot. That doesn't matter too much if you don't think you'll ever need to take it apart again - there are lots of saws made in the dying days of wood handles that have the bolt-holes punched through when in the handle. It's a real struggle to get them apart sometimes.

I wouldn't worry about affecting the temper of the plate however you choose to drill it, I've not had that happen even drilling quite thick plate (~1mm), but using cutting fluid is always advisable. An old fitter showed me a technique for drilling hardened steel using an ordinary drill bit. It involves squaring the end of a nail, chucking it in the DP, and holding it hard on the spot you want to drill at high speed to get it red hot. Let it cool in air & you can then drill through the softened spot with an ordinary HSS bit. He demonstrated the technique by drilling a hole in an old file, & I was interested to note that the metal a mm from the periphery of the hole was still file-hard..

Cheers,
Ian

 

[Tony Zaffuto]

I use hand punches. For thinner dovetail saws I have used the small hand punch pictured, but for full size handsaws the bigger "Whitney" punch is easier. For accuracy, I locate the hole positions using the saw handle as a guide, and centre dimple the location using a transfer punchView attachment 127049. This dimple then locates on the pin of the hand punch

I have used the smaller “Whitney” punch on multiple blades, probably up to 0.035” thick (thicker dovetail, carcass blades). I do it similarly by position the saw handle, then use an appropriate size center punch, for the hole.

I would advise that modern punches may not be hardened the same as the 70 year old Whitney I have.

I also, for a thicker saw plate, after punching the hole locations, spot heated the punched spot with a butane cig lighter, then easily drilled. Keep the heat very localized. I liked using a punch much better though!

 

[gmercer_48083]

Pgrbff,

I have done this several times... and found this cobalt bit to be the best at a reasonable cost. I make a plywood guide with pre drilled holes to clamp the blade (on a drill press) with another piece of plywood under the blade. make sure it is clamped tight to the drill press table... then place a drop of oil into the guide hole to cool the bit, and use medium speed and light steady drill pressure when drilling. Once the first hole is drilled... place a drill bit into the first to use as a drift to keep the blade located correctly on you drill jig and then continue /set up the next hole the same way. If it has more holes, use additional drifts as required.

This is the type of bit I use (made by Dewalt) DEWALT 1/4-in 4-1/16-in Cobalt Twist Drill Bit in the Twist Drill Bits department at Lowes.com

 

[redhunter350]

I recently sent my 20tpi c/c dovetail saw blade in for sharpening. It's a long process, my wife took it to England when she visited, posted it and it was returned to my sister-in-law before posting it back to me.
For some reason, and it only arrived yesterday, so I haven't had an opportunity to call them, they have replaced the blade entirely. Very kind of them seeing as the current price for the saw is over £150.
How do I make clean holes in the blade for the handle? I can't imagine it will be very easy to drill a clean hole through such thin steel even with a quality cobalt drill bit.

I think the first thing is to contact the manufacturer and ask their advice, otherwise assuming the top blade is your original? I would use this as a pattern to make a simple drill jig that locates on the LH & Top edges of the blade, use say aluminium or WHY drill though the original blade holes then transfer the jig to the new blade etc. It does of course depend on what facilities and tools you have. Test a HSS drill on your old blade, run not too fast and plenty of lube, if it’s not up to the job buy carbide, EBay would be useful here. Beware cheap diy HSS much is poor quality make sure it’s a top quality drill, lots of engineering industries in the north of Italy and lots of good tool suppliers! Good luck and hope you solve your problem

 

[xy mosian]

Interested to see how you get on as I have some hardpoint sawplates which I'm guessing
will be a whole lot easier to file than some of the old saws I've picked up cheap, not done a dovetail saw yet, the few I have filed had hard spots and pretty much wiped the files out after one profile job.

I managed to sharpen a Hard Point saw with a diamond needle file. Not quite as pretty as a standard saw file on an old S&J tenon, but workable.
geoff

 

[Ttrees]

Been considering those diamond files too, just haven't found some for cheap.
Seems you need buy a set, and always wondered if they were any good compared.

Interested to know how it held up to the induction hardened teeth.
Having also attempted with a hardpoint saw, it seemed about the same hardness as some hard spots I've encountered.
I still managed to have some life in the largest of the saw files afterwards to do another profile job for a panel saw, but seemingly to me the smaller files get damaged quite a bit easier.

Be nice to know if folks switch to diamonds if a hard spot is encountered.
Might save me looking for singular three corner needle files again.

Not that I've worked on many saw plates maybe four,
but seems to me that all the nice handled brass backed pistol grip dovetail saws for cheap out there, all look similar.
Most of the bargains (if you like above abutments) are real old 19th century ones, and have dark black rust, which I guess means they're hard, brittle, saw file eaters,
hence the good deal as no one wants to touch them.

(going by the "buy it now" choices, which most of the knowledgeable folks have likely avoided)

Even bought myself a wee micrometer for the job of replacing a saw plate if necessary, parkie ones for a tenner in liddles, seems nice, and likely good enough to measure saw plate precisely, including set also.
Don't mind softer plate, if it means I can get use from an extremely dull file, or even the diamond should they be slow compared.

Tom

 

[xy mosian]

Been considering those diamond files too, just haven't found some for cheap.
Seems you need buy a set, and always wondered if they were any good compared.

Interested to know how it held up to the induction hardened teeth.
Having also attempted with a hardpoint saw, it seemed about the same hardness as some hard spots I've encountered.
I still managed to have some life in the largest of the saw files afterwards to do another profile job for a panel saw, but seemingly to me the smaller files get damaged quite a bit easier.

Be nice to know if folks switch to diamonds if a hard spot is encountered.
Might save me looking for singular three corner needle files again.

Not that I've worked on many saw plates maybe four,
but seems to me that all the nice handled brass backed pistol grip dovetail saws for cheap out there, all look similar.
Most of the bargains (if you like above abutments) are real old 19th century ones, and have dark black rust, which I guess means they're hard, brittle, saw file eaters,
hence the good deal as no one wants to touch them.

(going by the "buy it now" choices, which most of the knowledgeable folks have likely avoided)

Even bought myself a wee micrometer for the job of replacing a saw plate if necessary, parkie ones for a tenner in liddles, seems nice, and likely good enough to measure saw plate precisely, including set also.
Don't mind softer plate, if it means I can get use from an extremely dull file, or even the diamond should they be slow compared.

Tom

Hi Tom,
I had smoothed/ruined a saw file on a hardpoint saw in the past. Hardpoint spotted from the blueish induction hardened tooth line. I was asked to sharpen a hand saw, about 20", 500mm, and I picked up a diamond triangular needle file from an Aldi, or Lidl, set as an alternative. Both the saw and the file survived which I took to be a win. Sadly the shops mentioned above don't seem to get those sets in very often but I will certainly buy another.
Ezelap:- Ezelap Diamond Needle Files - Ezelap needle files do sell them separately if a little on the pricey side. Other retailers exist. It was from the Ezelap site that I learned of the different grades in diamond files existed.
I realise that a true saw file has a radius to the corners, and I believe this was introduced to prevent splits starting at the root of the gullet. I have not heard of anyone having that splitting problem. Perhaps I have it all wrong.
I think the dark black rust you mention may be a coating carefully crafted from linseed oil, for preservation, and the dust/grime of everyday use. I tend to think an old saw with that sort of patina has been well used and cared for.
geoff

 

[Ttrees]

I must take a photo of what I'm talking about, what could be described as a
brittle sawplate, its a ways beyond just a patina.
Few hard spots on the saw below, not a good example.

Don't have any photos of the two examples I have, as it was very difficult to sharpen one of them,
the dovetail saw, not done yet and appears the same or worse again.

My double extra slim file Vallorbe I think? seems a bit large for it, as in the edges are very rounded.
Even if sharp corners were a concern, one could go back and sort that out with a dull saw file.

Thanks for the link, those last two files look the ticket, I'd snap them up for a tenner if they were local.

 

[pgrbff]

Thank you all. The supplier says " use a man drill using a titanium drill to do the holes. Often with the handle on so it all lines up. "
I assume they mean TiN coated I think will not cut as well as a good cobalt drill.
I guess I'll just have to bite the bullet and hope it doesn't go too wrong.

 

[pgrbff]

Came across this quite by chance. The gentleman sells handmade saws and associated tools and bits N pieces for saw making.