How to sharpen M tooth cross cut saw?

[philrosenberg]

Hi
I'm pretty new to woodworking and recently bought a job lot of vintage hand saws. I have sharpened up the back saw and one panel saw as rip cut saws, but could do with a cross cut saw too.

One of the saws is a 24" M tooth saw - you can see why it is called this from the pictures. My understanding is that this type of tooth is specifically for cross cuts, so should be ideal for my needs.

However, I cannot work out how to sharpen it and can't find any resources online.

It looks as though both teeth within a pair are set in the same direction. I presume it needs some fleam, given it is for cross cutting. But all the online tutorials assume alternate teeth set in opposite directions and show how to file to give fleam for that setup.

I also found some info that the M teeth may act as both cutting teeth and rakers, so maybe that effects how they should be filed.

If anyone has any idea how to sharpen this type of saw, I'd love to return this tool to service.

As an additional note, the handle could do with a little TLC, but the fixings have no screwdriver slot. Would they be rivets rather than screws and need drilling out to remove the handle?

 

[Bod]

https://www.fhwa.dot.gov/environment/re ... 22/toc.cfm
This website has the sharpening information, for that shape of teeth.
The handle is most likely riveted, try squeezing the rivets in a big metalwork vice, they might tighten up.

Bod.

 

[dannyr]

Yes - I always assumed that M teeth had one each way on each M.

I have a couple of similar looking saws, (farmers/docking or greenwood) but 'American' tooth pattern (3 teeth between each gullet) - definitely fleam and alternate set. Work well, but I tend to use a bow saw for those jobs.

 

[philrosenberg]

Thank you for the links I had a good look and did some more googling.

I found that tautahi racing axes and saws sell modern M tooth saws and have a diagram on their web page showing exactly how they are filed. Sorry I can't post a link as a new user.

It seems like these saws are more similar to cross cut panel saws than tooth and raker saws.

Basically both teeth on one M are filed on the same side, then the whole M is set, then the next M is filed on the opposite side and set the opposite way. It's just like a cross cut panel saw, but instead of each alternate tooth being filed and set opposite to its neighbour, we file and set two teeth the same way, then the next two.

I found mention that it is possible to set a few of the Ms as rakers. So I guess you could do set left, set right, raker...

I did wonder if the two teeth on one M would be set different amounts. This way, the first tooth is cutting down and the second is widening the kerf. Any thoughts?

Thanks for the help

Phil

 

[dannyr]

Sounds like they will be very much a log saw if sharpened like this (for big logs) - or at least for very thick beams.

"Three teeth rule " is good for most saws, but when sharpened/set like this might need more. Those starter teeth at the end will help.