Wide kerf table saw blades safe for non-through cuts?

[uncleswede]

Hi,

Pretty much novice woodworker here.

Is it safe to use a table blade saw that is wider than the riving knife providing it's never used for through cuts?
Basically, I'd like to use a 6mm kerf blade for my DeWalt table saw (which has a 3mm wide riving knife) for box joints using a custom crosscut sled...

Cheers
CD

 

[Jacob]

Hi,

Pretty much novice woodworker here.

Is it safe to use a table blade saw that is wider than the riving knife providing it's never used for through cuts?
Basically, I'd like to use a 6mm kerf blade for my DeWalt table saw (which has a 3mm wide riving knife) for box joints using a custom crosscut sled...

Cheers
CD

Yes. The riving knife has to be narrower than the sawblade anyway or it'd bind. Ideally just a fraction thinner but anything is better than nothing. You can saw through without a riving knife too, but with caution, in case of timber movement snatching the blade. More likely to happen with thicker material.

 

[deema]

No! The riving knife should be slightly larger than the plate of the saw blade, but narrower than the kerf. Using a 6mm kerf blade is highly likely to have a plate size wider than your riving knife. The riving knife becomes useless. You need a riving knife matched to the blade.

 

[HOJ]

use a 6mm kerf blade for my DeWalt table saw (which has a 3mm wide riving knife) for box joints using a custom crosscut sled...

For your intended purposes a riving knife will play no part, you will only need to make a cut just over the crown of the blade, then pull the sled back.

Make sure you do the diligence on extra measures to cover the exposed blade

 

[Jacob]

No! The riving knife should be slightly larger than the plate of the saw blade, but narrower than the kerf.

OK yes that's what I meant - ideally. But a thinner riving knife would still be effective

Using a 6mm kerf blade is highly likely to have a plate size wider than your riving knife. The riving knife becomes useless.

No it'd still help with wandering bits of wood.

You need a riving knife matched to the blade.

Ideally.

 

[Sideways]

Let me rewrite your question as this is in no way worse and probably better:
Is it safe to use a sawblade without any riving knife provided it isn't a through cut ?

It's not impossible for the wood to twist and pinch a little but it won't close up the way a rip cut all the way through can.

Try to clamp something across to give you a crown guard over the exposed blade if you don't have a proper overhead mounted guard.

I wouldn't be handholding the wood to the fence myself. I'd want it clamped and my fingers far away.

 

[Jacob]

....

I wouldn't be handholding the wood to the fence myself. I'd want it clamped and my fingers far away.

Yes i forgot to say two push sticks every time!

 

[Sideways]

Yes i forgot to say two push sticks every time!

I said it for you and then changed it when I remembered that this is supposed to be box jointing using a sled