Brit (Andy)":1bjfofcm said:
Where things are falling down:
• Grinding of blank - woeful in most cases
• Tooth cutting - generally appears to be the least troublesome part. Poor results are from poor grinding rather than poor tooth cutting
The correct corner radii, forging the blank shape, the grinding of the blank and the quality control are the areas of most concern.
Supporting evidence for this statement.
This is a (genuine) Swiss manufactured Needle File. Note the grinding smoothness of the shoulder, which is indicative of the whole blank before toothing.
...and the subsequent teeth produced (even though they are Double Cut):
Note the beautiful stamping of the name that would have us believe that they indeed manufactured it themselves, rather than telling us it was made
for them by a rather well known first quality Swiss manufacturer:
One of my research assistants here actually spoke to them by phone a couple of weeks ago, and they confirmed that have not made their own files for about 20 years, and that they are now produced for them in India, with the exception of their Needle Files and Precision Engineer's Files. So there is no speculation here.
On the other hand, here is a file produced "elsewhere" (it is a 6" ****) What?
View attachment 6
That sort of blank grinding leads to teeth like this:
View attachment 6
and THAT leads to this:
And the pride of workmanship can be seen in the Logo:
Are you seeing any similarities between all these files?
- The grinding is the same
The tooth forming is the same
The steel colour is the same
They all have printed logos
The logos are all the same smudged black ink, and the same font
Other than that, the differences are.....what, exactly? Hmmm?
That poor standard of gringing leads to what may as well be a double cut tooth pattern -
which is eschewed for Saw Files because it doesn't yield a good surface.
I go back to my Plane Blade analogy: you must have polished surfaces to get a proper edge. We do not need (even close) to a polished surface for a file blank. However, I do believe that they should at least
not be ground with a rock picked up from the yard (I know that's a cheaper method, but really....)