Help! Sizing table saw blade correctly...

[Bojam]

I recently bought a used Jet JPS10 hybrid table saw. It still has the orginal blade, which is probably rubbish and certainly old at this point.

I need to replace the blade and figured I'd buy a rip blade and a crosscut blade from CMT or Freud or whoever.

But it is proving harder than I expected. I need a 10" blade so either 254mm or 250mm would work. The arbor is 5/8" but I could buy a reducing bush so no problem there.

The issue is that on the splitter and on the riving knife it says that they are "only for use with 10 inch blades with 3.0mm MIN kerf width and 2.0mm MAX body (plate) thickness".

Almost all the standard kerf (i.e. 3.2mm) blades that I can find - and I've searched extensively online - have a plate thickness of 2.2mm or more. Thinner kerf blades i.e. those at 2.8mm have thinner plate thicknesses.

So what to do? I obviously can't exceed the 2.0mm plate thickness or the riving knife / splitter would be doing nothing. But I don't know if I can get away with a 2.8mm kerf when the min is specified at 3mm?

There doesn't appear to be a replacement thin kerf riving knife available for this saw.

NOTE: The only blades that I can find are these Trend blades: rip blade, crosscut blade. But I suspect they are probably not very good. There is also this general purpose Freud blade but the rounded teeth, I think, are principally designed for material other than the exotic hardwoods that I generally work with (I live in Brazil) and a 40T blade is a compromise solution anyway.

Helpful advice gratefully received!

 

[Sideways]

Do you have a vernier caliper to measure the actual plate thickness of the riving knife ?
Do that and let us know before anything else.

The riving knife has to fit inside the kerf, so if it's 3mm, it will also work with a 3.2mm kerf blade.
The riving knife has to be thicker than the plate of the blade or it won't prevent a cut pinching shut and binding on the blade. If it turns out that the riving knife actually measures 2.5mm, you could probably use a 2.2mm plate blade.
Notionally, I'd like the riving knife thickness to be halfway between the plate and kerf widths but there isn't a rule that says it has to be and saws are supplied new that don't meet that.

 

[Bojam]

Do you have a vernier caliper to measure the actual plate thickness of the riving knife ?
Do that and let us know before anything else.

The riving knife has to fit inside the kerf, so if it's 3mm, it will also work with a 3.2mm kerf blade.
The riving knife has to be thicker than the plate of the blade or it won't prevent a cut pinching shut and binding on the blade. If it turns out that the riving knife actually measures 2.5mm, you could probably use a 2.2mm plate blade.
Notionally, I'd like the riving knife thickness to be halfway between the plate and kerf widths but there isn't a rule that says it has to be and saws are supplied new that don't meet that.

Hi Sideways, thanks very much for your reply. The riving knife and the splitter are actually 2.3mm thick. So I am going to take some Freud blades that have a 1.8mm plate thickness and a 2.8mm kerf. This would exactly meet your half way between ideal case. Sound ok?

Also for reduction rings, the ones Axminster sell are 2mm thick so won't work with the 1.8mm plate thickness. CMT offer 30mm to 5/8in rings with 1.4mm thickness. Is that going to be ok? My understanding is that they just must not be thicker than the plate. No issue with them being 0.4mm thinner right?

Cheers!

 

[Sideways]

You've understood just fine. 1.8 or 2mm plate, 2.8mm or greater kerf sound fine with a 2.3mm riving knife.
Reduction rings just have to be thinner than the plate so the flange washers grip the blade plate, never the reducer.