What angle for P/T blades?

[Mister S]

Just about to sharpen the blades on my P/T to take out some nicks. Any idea what the right angle should be. I used to have it written down "somewhere safe" after I read a magazine article a while back, but of course now I can't find it.

Steve

 

[Steve Maskery]

It doesn't matter very much.
The angle you grind is only the clearance angle. The cutting angle is set by the cutter block.
I have my own ground at 40 deg and I hone them at 42 deg. But at the Community Workshop where I help out the P/T blades are ground at 45 deg. So why not just measure the existing grind with a sliding bevel and stick to it?
Another opportunity to plug
this
S

 

[carlb40]

Not sure if all knives use the same bevel angle or not? On my axi CT 150 the main angle is 40 degrees, so the secondary bevel will be about 42 degrees.

 

[WellsWood]

Agreed, it depends on the angle the knives are set at in the block. I use the same angles as above on my Jet - about 40 for grinding and a bit more for honing on a Maskery style jig - works for me. Pretty sure my previous planer, an Axy CT150, were the same. Like Steve says though, why not just measure the existing angle and use that?

 

[Mister S]

Thanks for the replies guys. I can (and will) measure the existing angle, but I already had them sharpened by a local firm so they may not be the original ones. I just wondered what other people use, but I hadn't thought of the possibility that it may differ between machines. And thanks too for the reminder about the honing jig design, which I'd forgotten about. All food for thought. I guess as long as there is clearance, anywhere between 42-45 degrees sounds out right (after honing).

Thanks
Steve