Blade kerf and riving knife

[HexusOdy]

I've always used Freud blades so when buying a new blade to replace the one that came with my table saw I got the Freud Pro LPM30.

What I didn't twig is they are 2.8mm kerf where the riving knife is 3.0mm (as is the old blade). What's my best option?

Grind down the knife, buy a new blade or can you buy a new knife?

I'm guessing new blade is best option but Freud don't seem to offer a 3mm kerf. Any suggestions for a good blade?

 

[Mark-numbers]

surely wouldn't that much of a ball ache to take off .2mm off the riving knife?

 

[blackrodd]

I would make a card pattern of you're riving knife and have one made up to 2.5mm thick and not spoil the original item.
Otherwise, Should you ever find a saw blade the right size you'll be stuck, and bearing in mind Sod's law?,---------
Just like waiting for a 'bus, none for ages, then 3 come along all at once!
Regards Rodders

 

[Steve Maskery]

RKs are very important pieces of kit. The good news is that you can probably get away with just two.

A RK shoul be thicker than the blade plate (i.e. the thickness measured at the bore hole) but thinner than the kerf (the thickeness of wood removed by the cut of the blade)

Traditionally the blade kerf is 3.2mm (1/8") on a 2.something mm plate, so a 3mm RK is perfect.

For a Thin Kerf Blade of,, say, 2.8mm kerf on a 2.4mm plate (I've just plucked those numbers out of the air, I can't remember what they really are, I'd have to look them up) then a 2.5mm RK would be perfect.

We are trying to fill the gap left by the saw cut, without impeding the path of the workpiece. In that way the workpiece does not nip up on the rising part of the blade and hit us in the face.

 

[custard]

What's my best option?

Grind down the knife, buy a new blade or can you buy a new knife?

Buy a new riving knife from the saw manufacturer.

What's your brand of saw, most manufacturers offer a range of different thicknesses across both riving knives and splitters to cover exactly this eventuality.

Good luck.

 

[HexusOdy]

Unfortunately it's a Taiwanese brand called Kufo. It's a great saw but parts are not easily available.

 

[Steve Maskery]

It's not too difficult to make your own. You can't use ordinary mild steel, it won't stay flat, but you can get Gauge Platein various thicknesses, metric and imperial. Try Cromwell.
You do have to be careful when cutting and drilling it, it heat-hardens, but a couple of hours with hacksaw, drill and file, using the original as a template, will see you up and running.

 

[marcros]

i disagree with Custard, for the first time ever

I have not seen a rage of riving knives from most manufacturers, even though it would make a lot of sense. Perhaps professional kit is different in this respect, and I only speak from looking at lower end saws.

I would use the existing knife to make a template, and make a new knife from gauge plate. it is pretty simple, I have made one myself, so it isnt rocket science.

 

[woodpig]

I doubt you'd get 2.8mm thick ground flat stock off the shelf and you may even have to search quite hard for 2.5mm.

Surface grinders are useful bits of kit but sadly I don't own one or I'd offer to grind some 3mm GFS down to size for you... :lol:

 

[Steve Maskery]

I can't find 2.5 on the Cromwell site, although I'm pretty sure it exists. There is 2.2 here:
http://www.groundflatstock.com/Shop/Cat ... uctID/3203
and the tolerances suggest it may be up to 2.53mm, so I'd give that a go.

You wouldn't want 2.8mm anyway, it needs to be somewhere between the thickness of the plate and the kerf.

 

[Steve Maskery]

Here you go. 3/32" is 2.38125mm
https://www.cromwell.co.uk/CTL4130326C
S

 

[woodpig]

I'm not surprised you can't get 2.5mm over here, I've not seen it before. As you say though 2.3 will probably do for a 2.8 blade.

 

[custard]

i disagree with Custard, for the first time ever

I have not seen a rage of riving knives from most manufacturers, even though it would make a lot of sense. Perhaps professional kit is different in this respect, and I only speak from looking at lower end saws.

I would use the existing knife to make a template, and make a new knife from gauge plate. it is pretty simple, I have made one myself, so it isnt rocket science.

I live and learn!

I was basing that on the fact that Hammer/Felder offer riving knives and splitters in 2.0, 2.4, 2.6, 2.8, 3.0 and 3.7mm thickness. They suggest the riving knife should be the thickness of the saw plate plus 0.2mm, provided this figure is still less than the kerf thickness.