|Microbevels front and back.|
|Use a jig.|
|Copyright (c) 2002-15, Brent Beach|
A High Speed Steel blade from the Stanley works in Hobart, Tasmania.
I bought this blade through Tony Blanks, an oldtools list member from Hobart. He found that the Stanley works there had been silver soldering (or perhaps brazing) High Speed Steel bits to standard Stanley plane blades. The blades were made shortly before Stanley closed the works there. It appears, from Tony and other sources in Australia, that Stanley did sell these blades. My blade may well have been a second - it did not get the Stanley mark. Peter McBride, another Aussie member of the oldtools list, has a web pages on these Stanley HSS blades. That pages includes pictures of the packaging, including Stanley's sharpening instructions.
This is a 2.3/8" wide blade, which I tested in a Stanley #604-1/2.
On the top face, the solder job was pretty clean. You can clearly see the change in steel type about 1/2" below the slot.
Not quite so clean on the back face. There is a defect in the join on the upper part of the image.
|This is a closer look at the defect (visible near the top of the above picture of the under side). The part marked Brazing? is actually a little more gold coloured than my scanner shows. Aside from this area, there is no indication of how the join was made.|
|Pro||An incredible iron, even by High Speed Steel standards.|
As with all my other tests, I honed three front and back bevels using 15, 5, and 0.5 micron 3M abrasive paper.
The front bevel, 200 X magnification, after the 0.5 micron paper.
The black mark in the primary bevel is a scratch I put there with a carbide scribe. I now mark all blades before the test to make sure I look at exactly the same part of the blade after each part of the test. In fact, a test involves front and back pictures before each stage of sharpening, before each 50 passes along the 4 foot Douglas-fir board, and after the test. This mark allows me to make further analyses of changes to the blade during the sharpening and testing.
The front bevel, 200 X magnification, after 100 passes along 4 foot douglas-fir board.
The wear bevel appears as a faintly darker band along the edge. It is about 1 pixel wide, or less than 0.00001".
The front bevel, 200 X magnification, after 200 passes.
By enlarging the picture (digitally) I can see that the wear bevel is about 3 pixels wide, or just over 0.00002".
As well as remarkably little wear, the edge shows none of the failure modes associated with A2 type steels.