Rip-cut and Cross-cut saw blades

[Karl]

I have been playing with my LV dovetail saw today, and am left a little confused as to why we have the difference between rip cut and cross cut teeth profiles.

The LV saw is 14tpi rip profile. It took 12 full length strokes to rip down to its full cutting depth in some 3/4" oak. It also took 12 full length strokes to rip down to its full cutting depth when crosscutting the same piece.

So why have cross cut? I know Tage Frid recommends that all saw blades should be sharpened rip cut, but this is obviously not accepted by the majority of the woodworking world.

Cheers

Karl

 

[Philly]

Karl
Crosscut saws work fine when ripping - but using a rip saw when crosscutting will soon give you the answer.
Cheers
Philly

 

[Karl]

That's what I did Philly - use a rip blade for crosscutting.

Are you referring to the breakout on the back of the piece?

 

[Philly]

Sorry, Karl - should have read your post twice before posting :lol:

A rip will always tear out on the back and, depending on the timber, tear on the front face of the cut as well. With sharp tools this is not so noticeable but as they become blunter from use this will be more obvious.

Try the same test on a piece of pine or tulip and you'll see much more obvious results.
Cheers
Philly

 

[pedder]

So why have cross cut? I know Tage Frid recommends that all saw blades should be sharpened rip cut, but this is obviously not accepted by the majority of the woodworking world.

Hi Karl,

sawing is not only about speed. A rip saw will cut cross cuts even faster than a crosscut saw. But it will leave a very rough finish. That being said going down finer than 16TPI the difference becomes small.

I think Tage Frids is misinterpreted. He used the continental saw sharpening system. And there are diffences between rip and crosscut. Rip is no fleam and rake from -6° to 6°. Crosscut is no fleam and rake about 15° to 25°.

Last weekend I made a saw with a mixed tooth configuration. Rake 20° and degressing fleam on the first 3" from 30° to 0°. You feel the difference.

Cheers Pedder

 

[woodbloke]

Wood fibres are like bundles of spaghetti...cross cut teeth when cutting across the grain are like knives that cut through the fibres at 90deg, in theory leaving little or no tear out. They will also work along the grain, but the chisel tooth configuration (as in a rip) is more efficient - Rob

 

[OPJ]

But surely, if you scribe your shoulder lines then, using a rip-toothed saw to cut across the grain isn't an issue?