Japanese wood saws cut the material on the pull stroke. This means that the teeth are angled towards the person using the saw.

If half way along the blade, the teeth started to face forward, then it would cut equally on both the pull and the push stroke.
-- xenzag, Feb 15 2021

But it still wouldn't cut any faster.
-- RayfordSteele, Feb 15 2021


[Rayford] Yes, but on the plus side, it would be much harder to use
-- hippo, Feb 15 2021


I think there are some saws that cut equally well on the pull and push stroke that feature symmetrically shaped teeth. I think I used one to lay a hardwood floor that worked like this - it also featured a set of teeth on the curve of the top edge - used for doing "blind cuts" i.e. starting a cut in the middle of an already laid panel - google tells me that the Japanese equivalent of this last type is called an Azebiki, and I suspect they might feature this pull/push feature, as the action needed to start off such a cut is very much a forward-backward scraping one until you manage to poke through and can do a more traditional sawing action with a different saw. The good thing about pull-cut saws is that because they're under tension, the metal can be thinner, so you get a smaller kerf. You'd (possibly) lose some of that advantage if you wanted them to work on the push cut as well. (Good quality) western saws are quite amazing when you consider how they taper from thick at the top edge to thinner at the business edge, to give enough strength to avoid bowing under the stresses during the push stroke.
-- zen_tom, Feb 15 2021


Doesn't make any sense, unless it's a two-man saw.
-- FlyingToaster, Feb 15 2021


//don't you lose that advantage by pushing?// No - the forward facing teeth make an identical cut, but they only make their cut on the push stroke
-- xenzag, Feb 15 2021


Better to have the teeth facing forward on one side and backwards on the other. Then you just take the saw out of the slot at each end of the stroke and flip it. Assuming the removal, flip and re-insertion takes zero time, this will make your saw cut twice as fast.
-- pocmloc, Feb 15 2021


Or have each tooth of the saw mounted on a tiny, motorised pivot. Then when you have pushed the saw through the wood, each tooth would pivot to face in the opposite direction, ready for the 'pull' stroke. This way, you'll be able to cut in both directions.
-- hippo, Feb 15 2021


I think a one man cross-cut saw fits this description.
-- 2 fries shy of a happy meal, Feb 15 2021



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