Recommendations on saw steel

[Ron Bontz]

Interesting thread. Thanks for posting. I don't wish to hijack the thread but I would like to ask George and Robert.. Just how much taper is just enough? ie: if you have a 0.040 x 26" plate toothed at say 7ppi rip. Do we just hit and miss and keep increasing until we think it is ok? I only ask because when I made my large tenon saw with 5" under spine and 0.032 plate; I toothed it at 11ppi rip. It required almost 0.005" of set per side before it felt "right". Thanks.

[Jack Curtis]

If you decided to taper your saw, I'd recommend doing it with a scraper, preferably a sen (Japanese tool for scraping metal).

[Robert Rozaieski]

Ron,
Many of the old saws were tapered at least that much at the toe. Keep in mind though that the taper on those old saws was least at the handle and most at the toe. It was not a consistent taper down the whole back of the saw. I think this was largely due to the large sandstone wheels and freehand grinding that was done to introduce the taper.

I couldn't tell you how much taper would be needed though. It depends a lot upon the woods being used and what kind offeel you are going for and whether or not you want to run any set at all. Suffice it to say though that the less set you want to use the more the plate would need to be tapered.

[Isaac Smith]

When I made this patternmaker's saw, I tapered the plate by scraping one side. I tried using a belt sander first, but it was difficult to control, so I took a file and sharpened the end. I tapered it by about .007" over the depth of the 1 1/2" blade. Even in a blade this small, it was a fairly time consuming effort. pm-saw-4.jpgpm-saw-5.jpgpm-saw-6.jpg

[Mel Fulks]

Aparantly it is difficult even for the saw manufacturing companies since for years some have been marking them "taper ground" without actually doing it.

[george wilson]

Trying to belt sand,or otherwise dry grind a saw with power tools is very,very risky. In an instant,the thin steel can suddenly bow into a convex surface that you cannot make flat again without equipment that most woodworkers don't have. I have a furnace 22" deep,which might not be deep enough for some blades. What I'd do is clamp the warped blade between 1/4" plates of hot rolled steel,and re temper the whole assembly in the oven while it is clamped tightly.

We used to do this to re flatten silver trays,when I was helping to make gifts for Reagan to give out. We'd clamp the hammered,and warped tray between steel sheets sawn to the shape of the tray. In this process,we'd heat the assembly red hot and leave it to cool overnight. The tray would then be restored to flatness beautifully.

The scraper is a valid idea that was once used on sword blades and other steel items. But,saws are at about 52 Rockwell. You might need a HSS scraper to do it. I helped the Gunsmith Shop to make a sword scraper,but it was very different from the scraper in your picture. It looked rather like a Stanley #80 scraper,but solid steel with the base ground hollow. It was resharpened by grinding the front edge sharp cornered,and was pushed with 2 hands. A much heavier,more powerful scraper that was forged out.

[Jack Curtis]

http://www.daikudojo.org/ShopTalk/metate_article.htm talks about Japanese saw metate, which includes sharpening and tapering and show some sen. As nearly as I can tell, everything there is appropriate for better made western saws.