Saw sharpening files 101

[FenceFurniture]

A point of interest to note. Last Sunday there was a fairly hot thread running elsewhere on the forum, talking about the absurd price differences between retail goods in Australia, and identical goods retailing overseas.

One of today's packages came all the way from Melbourne in a 3kg satchel (the smallest they had).
The contents weighed 100 grams.
The delivery cost for the 920km trip was $13.00 (ex GST)
There were two files, one 5" EST and one 6" EST, at $9.45 and $10.18 (ex GST)
There was also a 1.5% surcharge for using a credit card.

The other bag came from Europe, approx 17,700 kms or 19 times the distance from Melbourne.
The contents weighed 90 grams.
The delivery cost was was 7 Euros, or $10.00 at the current lousy exchange rate.
There were five files, but I'll just quote two of them (the same two as above, but smaller). The first, a 5", but DEST, not EST was $5.88, and the second 6" DEST, not EST, was $6.36
There was no surcharge for using a c/c.

[Sawdust Maker]

and no doubt you only shopped os to beat the GST

[pmcgee]

Hmm, feel like bit of a chunda meself! Those files are simply not fit for any purpose, are they?! So has the "recommended" list just shortened by another brand?

Two questions ...

What would the original files - blacksmithed and hand-cut - look like, that close up?

Regardless of what it looks like - how does it perform?
How to benchmark the life and/or quality of the performance?

Cheers,
Paul

[FenceFurniture]

SPECIAL BULLETIN FOR THE TAPER TOUTERS


I have some concerning news. I do not know what sort of taper you have previously been enjoying (in terms of the angle and length of the tapered part), but for your arguments to hold water (even a drop), then they'd better be steeper angles than the new offerings.

4" DEST (arrived today)
Length of tapered part 10mm
Difference in width per edge 0.075mm (3 thou)
Angle of taper 0.43° (that's right, less than half a degree over 10mm)


5" EST (arrived today)
Length of tapered part 40mm
Difference in width per edge 0.3mm (12 thou)
Angle of taper 0.43° (that's right, less than half a degree over 40mm)


6" EST (arrived today)
Length of tapered part 25mm
Difference in width per edge 0.2mm (8 thou)
Angle of taper 0.46° (that's right, STILL less than half a degree over 25mm)


Now I ask you, what use is that? Furthermore, what use is a taper that is a whole 10mm long, with a variance of 2 thou, or 4 thou if you count both faces being in the gullet?

I'd be very interested to know the specs on what is regarded as a good taper file, where the taper ia appreciated for what it is known to do.

Come on, sock on the block

[FenceFurniture]

Regardless of what it looks like - how does it perform?

We'll know all that and more in the coming weeks. And yes, I agree, if it still performs, who cares.

Chatting with Claw on the phone and by email, and a thought has occured to me, and I'd very much like the input of the hard heads here, particularly Ian (and I trust that the forum software will do it's censorship job, as this is a direct quote):
Apart from obviously needing good steel, hardening and tempering, I reckon the next most critical factor is smooth grinding and good tooth cutting as a result. I just wonder if the the #### grinding that leads to #### face teeth is causing a fracture point for the corner teeth to crack off........

[Claw Hama]

I will be happy with any taper FF, once my end is in its all go go go I did notice with the Liogiers we got before the taper was shorter than with some of the older files I have. Still seems to do the job. And as per my email, the bad grinding and deep gouges is the logical place to snap a tooth although not having broken any and not seen any, who knows.

[pmcgee]

We'll know all that and more in the coming weeks. And yes, I agree, if it still performs, who cares.

Two more thoughts ...

What does one of these new files look like after a few swipes of filing?
What does a 'nice' file look like after a few swipes of filing?
Paul

[FenceFurniture]

This is what I was talking about yesterday. These teeth, with a deep score in the face, look like they are ready to snap off at the slightest provocation.



With that in mind I'll take another pic of them this morning to have a better look.

[FenceFurniture]

What does a 'nice' file look like after a few swipes of filing?
Paul

Arrggh, what "nice" file? Where do you get one of them?

[IanW]

.......I'd very much like the input of the hard heads here, particularly Ian (and I trust that the forum software will do it's censorship job, as this is a direct quote):
Apart from obviously needing good steel, hardening and tempering, I reckon the next most critical factor is smooth grinding and good tooth cutting as a result. I just wonder if the the #### grinding that leads to #### face teeth is causing a fracture point for the corner teeth to crack off........

Has this been linked to in the discussion yet? This bloke is talking about the quality of hand-cut vs. machine-made files more than a hundred years ago (perhaps file problems are not so new after all! ). I was trying to find out how modern files are generally made, (with no real success), but it would seem that whether hand or machine-made, they are done by an 'upset' method, i.e., each succeeding tooth is struck on the annealed blank with a sharp chisel, they are not ground. So the file would be in a softened state when struck & has to be hardened afterwards. The point of this is that it's the quality of the blank going into the toothing machine that has caused those linear indentations & 'scratches', so if the hardening process is done properly, they could still cut ok, though possibly not as smoothly as I would like for a saw file. However, experience has taught me, as it probably has most of us longer-toothed folks, that if one pat of a multi-step manufacturing process is hurried & bodgied, the others most likely will be, too. But let's approach the testing with open minds.

OTH, if you read the piece I linked to, you'll see he is burbling on about uneven teeth being preferred - the hand-made files were claimed to be superior because of their slight imperfections! perhaps these files will be the best ever.

Two more thoughts ...

What does one of these new files look like after a few swipes of filing?
What does a 'nice' file look like after a few swipes of filing?
Paul

We can't answer the first question yet, Paul.....

For the second question, I can give you some sort of answer: I expect to see very little change after "a few swipes", apart from a faint shiny strip along the tops of the teeth as the oxide wears off. After many more swipes, depending on the hardness of the substrate being filed, the polished area will be wider, indicating the tips of the teeth are worn & dull (something you will have already known because of the reduced 'bite' of the file). If you are cutting an even surface, I expect this polish to be even, demonstrating that the tips of the teeth are all straight & even. The teeth FF photographed are anything but even across their width, though possibly consistent in (maximum) height, so they may not cut as badly as the pics would lead us to expect. The proof of the pudding will come with the eating....

So let's get out the spoons.....
Cheers,

[johnredl]

Hey John, any chance of a pic of this big sucker?

Yes, I'll do it tonight

[FenceFurniture]

I was trying to find out how modern files are generally made, (with no real success), but it would seem that whether hand or machine-made, they are done by an 'upset' method, i.e., each succeeding tooth is struck on the annealed blank with a sharp chisel, they are not ground. So the file would be in a softened state when struck & has to be hardened afterwards.

Yes indeedy

NOMENCLATURE and DEFINITIONS

Cutting – the process of punching the teeth or ridges into the face of the file. Material is NOT removed from the file, hence the cut area is thicker than the file blank (as can be seen by inspecting the uncut area at the shoulder).

Milling – the teeth are milled out of the file blank. Material is removed and the toothed area is the same thickness as the untoothed area.

The point of this is that it's the quality of the blank going into the toothing machine that has caused those linear indentations & 'scratches', so if the hardening process is done properly, they could still cut ok, though possibly not as smoothly as I would like for a saw file. However, experience has taught me, as it probably has most of us longer-toothed folks, that if one pat of a multi-step manufacturing process is hurried & bodgied, the others most likely will be, too.

Yep, reckon it's a knock on effect. There is no way you can get good teeth out of a scratched blank. The pics show what is virtually a double cut file, but saw files are specifically single cut to get a superior finish. Not going to happen with these suckers. (one is tempted to use the Olde English "f" for an "s" there)

OTH, if you read the piece I linked to, you'll see he is burbling on about uneven teeth being preferred - the hand-made files were claimed to be superior because of their slight imperfections!

Yes, but he's referring to general filing, not the specifics of saw filing, where the bit being filed is only a miserable 0.5 to say 1.5mm thick. So, at any one time there can only be one, maybe two or three teeth in contact with the job, but with normal filing there can be hundreds at any one time. With saw files like those shown yesterday, if the teeth are of uneven height (and they very clearly are), then the file will be going up and down as it it crosses the saw plate - that doesn't sound desirable, and sounds like it will lead to jagging as a lower tooth is followed by a higher tooth.

perhaps these files will be the best ever.

Dream on my man.

[johnredl]

We should also think about what audience this body of information will be referred to by ... it is complete beginners that I am thinking of. People who may have picked up their first garage sale saw, or had some in the shed for a while, and are looking to do something about it. They can bodge a saw-vice if they have a wood- or metal-vice, but they need a/some files.

They need to hear about the quality issues and - if they are prepared to plan ahead - what sources to order from. But the Nicholsons are still an option in this situation when someone just wants to get in and 'have a go' without having to think too much about it - cos they're already gunna have enough to think about in the process of doing the sharpening anyway

Yes, this is where I am coming from! I am exactly the guy that you've explained. I need to make a saw vice, I've bought/obtained some saws, but need to learn how to sharpen them! It is interesting to read about all the tech stuff of saw sharpening, it reinforces to me that saw care is a profession, not just a hobby. But I am also the sort of guy that's happy to pay for quality.

[FenceFurniture]

This picture better illustrates what I meant by fracture points introduced by poor grinding. The closer to the edge that score mark is the greater the chance of fracture, because it has less of the face tooth supporting it.

[pmcgee]

Has this been linked to in the discussion yet? This bloke is talking about the quality of hand-cut vs. machine-made files more than a hundred years ago (perhaps file problems are not so new after all! ).

But the opposite view existed also - not just in this document - I've seen it a few times.

::I'm sorry ... maybe he was for machine-cut files. It's a bit hard to figure whose side he is on.

Making Files at Disston from "The File in History" - Disston & Sons, 1921

Modern practice has demonstrated, however, that the hand-cut file cannot possibly possess the same high efficiency that a machine-cut file does for the reason that the machine will do the work uniformly from the beginning of the day to its close.


During the cutting operation the blank is secured in a "bed" which travels back and forth under a chisel that "raises" the teeth at a speed the eye can hardly follow. When double-cut files are being made the blank is put through the machine and "overcut." Then the position of the bed is shifted to one side and the second cut, or "upcut," is put on, the teeth running in an opposite direction. On some machines the chisel is turned instead of the bed.


This style of machine represents the highest development in file-cutting machines, and is one of the many reasons why Disston files are so superior, both in the efficiency and endurance of the teeth.