Is it possible to sharpen hole saws?

[heatherw]

And if so how?

We use hole saws quite a lot, and they wear out and we usually buy a new one. I always assumed that they're like hard point saws and can't be sharpened, but before throwing the latest one away, I'd like to be sure.....

Thanks everyone, I know someone out there knows the answer

Heather

 

[gregmcateer]

I'm not sure - never tried, but it must be worth a quick try with a small triangular file - pretty quick to give it a few passes per tooth and test it.
Do let us know - I for one am a stingy veil and would love to save on them!

Cheers

Greg

 

[RobinBHM]

I think hole saws have hardened teeth, they will certainly drill through mild sheet steel, so you may find a file may not do anything, you could use a diamond stone if you have one.

 

[flh801978]

I use a 1mm disc on an angle grinder to touch them up when blunt.
hold the A/G in a vice or clamp and offer the hole saw up by hand
wear eye protection etc

 

[heatherw]

Ok, I'll try that. One thing that confuses me is that the teeth aren't all the same size, there are groups of small teeth and groups of large teeth. This particular one says HSS bimetal on the barrel, don't know what that could mean? Might mean unhardened teeth? We use them almost exclusively on chipboard and they seem to wear out very quickly considering that they're supposed to cut metal.

 

[dc_ni]

Blades for bandsaws and reciprocating saws are often made with bimetal construction. The teeth, made of high speed steel, are bonded (by various methods, for example, electron beam welding or laser beam welding) to the high-strength carbon steel base. Such construction makes for blades with a better combination of cutting speed and durability than shown by non-bimetal blades

Just got that from wiki http://en.wikipedia.org/wiki/Bimetal

 

[Myfordman]

Assuming you are using the starrett type hole saws ( round cutters screwed onto arbour )
then you can buy tungsten carbide cutters which will last far longer in chipboard and save you money in the long run.

 

[Hemsby]

If it says they are high speed bimetal it is likely you will only be able to sharpen them with either a diamond file or grinding wheel.

Older hacksaw blades were obviously hardened to enable them to cut steel but if twisted they would break, later manufactured from bimetal, hardened teeth & flexible back, would tolerate being twisted.

Chipboard is probably the worst material you could be cutting with a hole saw. My advice would be to use the best quality saw you can afford but keep the speed down,

 

[Eric The Viking]

See if you can work out some fierce dust extraction arrangement, or a vacuum with a crevice tool: holesaws clog horribly, and overheat when they do. It takes the edge off the teeth in no time. A routine of "cut a bit; stop; clean hole and saw; repeat..." won't slow you up all that much, as the saw will be that much more effective.

You can also get diamond needle files cheaply. I've had my present set so long I can't remember where I got them, but the usual suspects (eBay or a shed probably). Mine have been badly treated but still work very well. The last job was cutting new teeth on a Bosch GOP blade (like Fein). I'd worn the blade almost smooth. I'm sure they'd do for touch-up, but it is time consuming.