Thread: Bahco saw file sizes

Originally Posted by Corneel

There are some knowledgable people about saw making here, so I've got a question for you all.

I would like to buy some packages of sawfiles and while browsing the Bahco catalogue, something peculiar caught my attention. What is really the difference beteen slim, extra slim and double extra slim?

They show this picture:

When I look at a slim, then a file with B= 6mm has a length A of 100mm (4").
The extra slim: B = 6mm, then A = 112 or 125mm (4.5" or 5").
And double extra slim for B = 6mm has a length of 150mm (6").

So, under what circumstanbces would I use a slim versus a double extra slim? In my primitive look on things I would say, take the longest possible file for a given size of B. They all have cut 2 and all have about the same tpi (23 or 24 teeth per cm).

Maybe the radius of the edge differs? I think so, but why is that?

If the have the same face width and the same tooth count per cm, then unless the radius of the edges differs the only difference will be the length of the stroke possible (longer is better of course). Even a face width variation will have little impact - as long as the face is >=2x the tooth face then it doesn't make a blind bit of difference as long as the corners are the same radius.

It's essentially all about the corner radius. For example (extreme) you could have a file that has a face 20mm wide and 300mm long and it will do an identical job as a much smaller file if the edges are the same. The file would be harder to handle than the smaller jobbie, but theoretically will cut exactly the same tooth.

In fact, you can sort of get away with a file face that doesn't cover twice the tooth face - it's the edge that does all the work, so a bit of overlap in the middle of the face wouldn't be the end of the world, but nor would it be desirable.

The catch is that the radius dimension is the one thing that is never specified properly these days. So you either have to do a visual inspection (a little vague perhaps) or cut a notch with each file to see how different, if any, the edge radius is.

I would be doubtful about trusting the classification or DEST, EST or ST for determining edge radius, mainly because I doubt that the manufacturers know as much as they should about it. I mean, they claim them as "tapers" and they are clearly no such thing (or at least not a proper taper). The closest I've seen (from current production) is the untoothed tip has a sudden taper, and therefore not worth a cup of cold water. That doesn't show much knowledge of their product, in my opinion

Isaac has some recommendations for selecting files here:
http://www.blackburntools.com/blog/c...m-now-selling/
I suggest they would be a pretty good starting point.

I don't know if you'll be able to find much xx-slim bahcos. We can't get them over here, and thus for backsaws on the small side, we have to rely on other makes. the one other thing that sticks out to me with bahcos, and maybe it's documented here, is that while they're edges are super consistent (and they are, the best I've seen of new files), they are a bit fat. They may do that for the purpose of making them more durable (because most people wear the edges out before the sides, unless you're mindful enough on something like a large ripsaw to really bias the file one way or another).

I just went down and opened my box of 4 x slims. I don't remember why I got them, but there's probably xx slim 6s that do about the same. I don't have xx slim bahco 6s to compare, so I can't tell you if that's true (it hinges on the edge thickness), but if the edge thickness is similar there's no reason to go with the shorter file, as brett and others say.

I'd rely on isaac and other guys currently filing to make recommendations for the small files where that fat edge makes a difference (if you try to use a 5 x slim bahco on a 15 point saw in a pinch, the gullets will hold wood. It'll still cut fine, but it'll be annoying to look at the saw tooth edge and see the teeth holding wood). I have done that in a pinch, but it makes the teeth look like hook teeth...it's pretty ugly.

(that was a bit of a response to other things, but I think at this point your issue is whether or not the edge fatness is the same. Until you can actually get the xx slims somewhere in small size, I'd assume that they're interesting to see on the chart but unavailable. Their listings have the xx slims over here, but the drop shippers coming directly from williams tool do not have any small xx slims, and I'm not even sure if they have 6 xx slims.)

For my dovetail saws, 14 and 18 tpi, I have used needle files from Bahco. They were good. And the teeth look nice.

I'll check out Isaac's blog first. Seems to be a good starting point.

Originally Posted by Corneel

I would like to buy some packages of sawfiles and while browsing the Bahco catalogue, something peculiar caught my attention. What is really the difference beteen slim, extra slim and double extra slim?

They show this picture:

When I look at a slim, then a file with B= 6mm has a length A of 100mm (4").
The extra slim: B = 6mm, then A = 112 or 125mm (4.5" or 5").
And double extra slim for B = 6mm has a length of 150mm (6").

So, under what circumstanbces would I use a slim versus a double extra slim?

Regular > Slim > X Slim > XXSlim is basically:
Coarse Handsaws 3 to 6 ppi > Handsaws 6 to 9 ppi > Handsaws/Backsaws 9 to 12 ppi > Backsaws 11 to 15 ppi

Originally Posted by Corneel

In my primitive look on things I would say, take the longest possible file for a given size of B. They all have cut 2 and all have about the same tpi (23 or 24 teeth per cm).

The TPI changes with length and cut (for saw files there is only one cut - 2nd, but 4 basic types) for American Pattern files, for Swiss Pattern files the TPI is not related to length, only to CUT, ranging from 0000 to 6.
Bahco Slim
BahcoSlimTable.JPG
Bahco XXSlim
BahcoXXSlimTable.JPG
You can see the differences.
Another issue with larger files and small teeth is that it is difficult to see where you are going (see my age in the header)

Originally Posted by Corneel

Maybe the radius of the edge differs? I think so, but why is that?

Most definitely the edge radius changes, a 150mm XXSlim (24 TPI) is the same width as a 100mm Slim (23 TPI), but has a narrower edge. The extreme case is Bandsaw Taper files which have a very wide radius to match the tooth shape. Looking at the illustrations in the 1942 Nicholson Catalog, Blunt saw files have a wider edge than Taper files of same type. I must get around to a gullet sampler on a piece of saw plate to illustrate the differences between tapers and brands (old and new - although I do not possess any Bahco files at present).

Originally Posted by Corneel

For my dovetail saws, 14 and 18 tpi, I have used needle files from Bahco. They were good. And the teeth look nice

Bahco needle files are American Pattern, not Swiss Pattern, and Smooth Cut (≈ Cut 2 SP) for 160mm length, Dead Smooth (≈ Cut 4 SP)for 140 mm. They are pretty good, but not as good as Vallorbe in my very limited use; Stewie uses Cut 4, I have used Cut 0 which is a bit coarse but ok for initial toothing

Get a range of files (Bahco or NOS) and do some test teeth on a piece of scrap saw plate to see the profile you might want/need.

Cheers
Peter

Can't really add much to what's been said. I read what Isaac's got to say & I think he covers the topic very nicely. However, I have to wonder if they are getting better files from Pferd over in the U.S. than we are seeing here. He says the one's he's tried were good, but the several lots I've tried were god-awful! Apart from inconsistency in corner radii, they were all far too brittle, and the corner teeth started breaking away after just a few strokes. In comparison, some NOS, U.S. made files I used last week held up (on the same saw plate material) many times better.

Somewhere in the old posts on files is a table showing width of the different sizes for American pattern files. What the table doesn't specify in numbers, but shows in silhouette, is the corner radii, which (should) diminish with decreasing slimness in each length, with DEST being the sharpest. They did so, once, but nowadays they are all over the shop! Where once you could use a 4" DEST file with confidence on a 15tpi saw, it's a very hit & miss affair with the files I've been using the last 10 years or so - I'm liable to end up with huge gullets & funny little spikes for teeth because the corners are more like those on a 6 inch file! The only truly reliable files I can get now, with corner radii fine enough to make appropriate gullets for small teeth (15tpi & more) are the needle files mentioned.

Cheers,

Originally Posted by IanW

What the table doesn't specify in numbers, but shows in silhouette, is the corner radii, which (should) diminish with decreasing slimness in each length, with DEST being the sharpest.

In all the vast amount of research that was done, it was the one fact that avoided detection. Apparently no living soul knows the answer to that particular question.

Originally Posted by IanW

However, I have to wonder if they are getting better files from Pferd over in the U.S. than we are seeing here. He says the one's he's tried were good, but the several lots I've tried were god-awful! Apart from inconsistency in corner radii, they were all far too brittle, and the corner teeth started breaking away after just a few strokes.

The sample size I had was small (a few boxes from a single order), so it is possible that they weren't entirely representative of their product. Or maybe yours were the outliers. Either way, it's sad that there isn't more consistency. At the time I wrote that, I knew of a couple of saw filers here that said they used the Pferd files and were happy with them (happy being a relative term considering what else is available).

As to whether they have different product lines, my gut instinct is no. It's not like we're overrun here with consumers clamoring for high quality goods. I'd lean towards the more "innocent" explanation of incompetence or indifference.

Today I have sorted my small collection of saw files. Most are from the F. Dick brand and probably about 5 years old. The others are Bahco.

foto (1).jpg

On the left a bunch of very small needle files. Then some XXS 4" etc all the way up to some regular 7" files. I can clearly see an increase of the corner radius. Overall the files really don't look very bad. In use they feel very hard, even a little brittle. I have filed several complete tooth lines with files like these and usually eat up a complete file on one saw plate for the rough work, and then sharpen with a fresh file. I have no idea how they compare with the oldies, because I haven't ever seen NOS for sale. So in my naievity I would say they aren't too bad.

Now I finally sorted this bunch, I have finaly a good idea how the various sizes look like, and am now able to answer my own questions.

Originally Posted by Isaac S

The sample size I had was small (a few boxes from a single order), so it is possible that they weren't entirely representative of their product. Or maybe yours were the outliers. .......

......As to whether they have different product lines, my gut instinct is no. It's not like we're overrun here with consumers clamoring for high quality goods. I'd lean towards the more "innocent" explanation of incompetence or indifference.....

Isaac, my comment re the quality of the files you were receiving was just a throwaway - I suspect you are absolutely correct in that it is much more likely to be a case of poor or erratic quality control than anything deliberate. I have used files from several sources, now, and they were all poor, but it's entirely possible they all came from the same original batch. There wouldn't be all that many saw files used in this country, so a few gross imported in a single batch would last quite a while, I suspect. There has been variation between lots, which suggested to me they were from different production runs, but I could be wrong, and it may simply be representative of the wide range of poor quality that is possible.

Saw files are now a niche market, like it or not; there are relatively few people in the western world filing hand saws, & fewer still who can remember what files were once like! Our best chance, I think, is that someone steps up and supplies the niche with a decent product. I'm not one to blame the tools, as a rule, but I make an exception when it comes to files. I don't know about anyone else, but I find it very difficult to do anything like a decent job of toothing saws with poor files, so I'm prepared to grit my teeth & pay a bit extra if I can get reliably consistent, clean-cutting files that don't fall to bits on the second or third stroke. I'm sure you could please almost everyone with a small number of well-chosen sizes, so you wouldn't need to produce an exhaustive range. I reckon you can cover the range for backsaws with about 3 sizes, but others may be a bit fussier....

Cheers,

Originally Posted by FenceFurniture

In all the vast amount of research that was done, it was the one fact that avoided detection. Apparently no living soul knows the answer to that particular question.

After I get my current backlog of projects caught up some I can take some measurements with my stage micrometer. Just about got the new steel framed storage shed into position.

Originally Posted by Corneel

Today I have sorted my small collection of saw files. Most are from the F. Dick brand and probably about 5 years old. The others are Bahco.

F. Dick source their files from Vallorbe (since 1993), so needle files are (hopefully) Swiss. Saw files will probably be the same as Grobet, ie made in India. Vallorbe chainsaw file boxes are still marked Made in Switzerland, both at F. Dick and in Oz.

Originally Posted by rob streeper

After I get my current backlog of projects caught us some I can take some measurements with my stage micrometer. Just about got the new steel framed storage shed into position.

Goodo Rob. I suspect that where it gets tricky is determining what the width of the flat is on the corner before it is toothed. My understanding is that the sharp corners (from the forging or whatever process) are then filed flat to a certain width and then they are toothed all round. The width of the flat filed corner will then determine the radius of the toothed file edge.

Pretty sure that's how it's done but not absolutely certain. Therefore determining what the flat filed width is after it has been toothed, and therefore deformed, could be tricky.

Originally Posted by Heavansabove

F. Dick source their files from Vallorbe (since 1993), so needle files are (hopefully) Swiss. They are.

Originally Posted by Heavansabove

Saw files will probably be the same as Grobet, ie made in India.

Yep, they sure are. That black Indian ink is the big giveaway.