Taper grinding the saw plate ?

Discussion in 'Saw Makers Forum' started by Magman07, Nov 7, 2011.

  1. Magman07

    Magman07 New Member

    Messages:
    1
    Hello all, this is my first post on the forum.

    I am in the process of making my first hand saw and in doing the research on saw types I see that some are taper ground. Can anyone tell me what the purpose for taper grinding a saw plate is?
    Some say it is to reduce binding some say weight is there any hard data on this?

    Thanks
     
  2. lui

    lui Most Valued Member

    Messages:
    77
    I taper grind all of my saws, making them thinner along their back edge. This has three benefits.

    It makes the saw lighter and moves the weight to the tooth line, this improves control of the saw when cutting.
    It makes the saw less likely to jam in the saw cut.
    It reduced the amount of set required, less set = thinner cut = less effort.

    In reality I'm not sure if the first one makes any differance, especially when compared to skew backed saws, but then again I'm not a big fan of skew backs, I find them a bit pointless.

    I like saws with weight, let the weight of the saw do the work for you.

    Regards

    lui
     
  3. Barleys

    Barleys Most Valued Member

    Messages:
    546
    taper grinding

    I'm very far from having the ability to work on saw plate, but I can pass on the info from some reading:
    Joseph Moxon's Mechanick Exercises (c1670) stresses the need for a saw to be thinner at the back - he writes in the most beautiful precise English.

    Sheffield saws were taper ground from very early times, notably the Kenyon saws in the Seaton Chest which Ken Hawley measured and showed highly accurate taper grinding in the 1790s (at least half a century before the micrometer was invented).

    Later Sheffield saws were given more taper the better the quality, down to none on the common quality items.

    And incidentally I am delighted to see no less than a saw maker himself deprecating the Disston skew back - I've often thought that it was more a marketing device than necessarily the major advance that the hype of the 1870s suggested. Geoff Tweedale notes that Disston was a hugely successful advertiser and marketer (plus a maker of fine saws). And was it widely copied because it was a tiny saving on steel per saw, adding up to big amounts when production was in the hundreds of thousands?
     
  4. TraditionalToolworks

    TraditionalToolworks Most Valued Member

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    181
    Howdy there Sir! lol

    Hope your doing well.

    There seems to be some controversy over how much taper may have been on the Seaton saws and/or if it was just imperfect steel.

    AFAIK, you must keep the speed of the grinding wheel slow so that the steel doesn't loose it's temper. I just posted in another thread that I've read Mike Wenzloff may use a Tormek, and that would make sense as it is slow and stays cool.

    Taper grinding doesn't interest me much as I don't use full size handsaws myself, except on occasion or for small cuts, say for molding. The rest of the time I use electrons to dimension wood, so that I can focus on what I do like, the joinery, detail work, and assembly...and I do all that with hand tools.

    Disston continually sacrificed craftsmanship for convenience/production continually in all his years. He himself made it so that people were not willing to pay extra to get tapering done. Or at least they were able to convince people to buy their inferior saws, as they were cheap. In those days people were really cheap, so the product that Disston produced fit the times I 'spose. We have much better options available today. IMO, the slitted/slotted back is a huge improvement. I'm certain Disston would have embraced it in favor of higher production, but the reality it is an improvement over the folded back.