Hand saw

Cheer yourself up by watching someone painstakingly restoring something most would regard as “junk”.

Tim

Would you know how to re-sharpen it if you wanted to? If not, why is that a problem?

Possibly true but I bet your builder doesn't sharpen saws and uses the same type.

All my builders bought cheap saws and threw them away after a couple of weeks. Way cheaper than resharpening them.

Of course they can be resharpened, but they tend to me made of softer steel with a hardened edge, and once that goes they don't last.

Probably a 'hard point' with induction hardened teeth. Mine is probably 30 years old & still going strong. I class it as a 'roughing' saw for cuts that don't have to be accurate or might have nails in or to take to a job in the car.

With many you can see the very narrow hardened edge as it is discoloured

- probably edge hardened using some very fast induction heating process.

And downgrades them for insulation cutting. I suspect modern saw steel is too hard for conventional filing anyway.

I think its the other way around. The steel is soft with a hardened edge. Once that has gone, the saw is effectively junk

I see them described as hardpoint saws.

Yes. However the steel must first be suitable for induction hardening. I am not a metallurgist but you can't harden mild steel without adding carbon in some form.

This is partly true. The teeth will be induction hardened and could not easily be resharpened with a conventional file anyway. So when it blunts it is in effect disposable.

However it will retain its edge for significantly longer than a traditional saw. It will probably cut faster, and also not be instantly blunted when cutting things like melamine faced board, chipboard, OSB etc.

Yup I sympathise, although doing a good job of sharpening a saw is a fairly slow process, and time is now no longer cheap. So often it is more cost effective and more productive, to buy a box of saws at the start of a large project - and just swap to a sharp one as the existing becomes too slow. The better "blunt" ones can serve as insulation saws etc.

A triangular diamond faced needle file works on hardened teeth. The main problem is that you can't reset the teeth after sharpening.

Not very hard to do...

I have sharpened a hard-point saw but I didn't dare to try to re-set it in case the points sanpped off.

I found the resetting tool simply wouldn't do anything.

Another thing that sounded good was a Spear and Jackson tenon saw which was Teflon coated. However after a surprisingly short time the Teflon wore off in the area of highest friction, leaving the blade to start to go rusty. Not a fan of the plastic handle either. Brian

Likely because it has hardened teeth. So will stay sharp for a lot longer than one designed to be re-sharpened. No matter how 'fine' that steel may be.