They all seem to be fine tooth saws, so only really suitable for shallow cutting, such as slotting screw heads. For deeper slots you need coarse tooth saws. Here's a picture of several saws (all coarse tooth apart from bottom right) for comparison:

Ideally for deep cuts with a coarse tooth saw the saw needs to hollow ground to reduce rubbing in the slot.

Andrew

If getting from Chronos then go with the 3" x 30T if you want imperial widths, none of their metric offerings look that fine (they do use one photo for all) so if you want metric then I would go to say ARC who have coarse ones.

Hardest thing is finding an arbor that is central. I have a stack of various saws from good makes. 3 arbors that cut on maybe 6 teeth if I am lucky. Note to oneself. Make an accurate arbor for the saw's.

Steve.

Steve.

I can't remember where, but recently I read that it is better to use course blades than fine. This is because each tooth needs a feed, so the more teeth the faster the feed rate and hence easier to feed too slow and rub blunt.

Made me feel better about the course blades I have.

Adrian

Both have their uses. It's all to do with the size of the gullet. With a fine tooth saw a large depth of cut is a problem as the gullet may get full of swarf, which will cause the saw to jam. For a shallow depth of cut (like slotting a screw head) a fine tooth saw is fine, and can be feed at a higher rate as it has more teeth. For a deep depth of cut a coarse tooth saw has a much larger gullet which will be less prone to jamming.

Andrew

Hi Dave, Guys,

It was not understanding slitting saws that caused a jam up when cutting aluminium on the mill, destroying the teeth on the plastic gear.

If I have to do a longish cut in any material I prefer to use the bandsaw. Otherwise its slow and steady with lots of lube. Trying to do a cut in one go doesn't take into account that as you cut the stresses in the material tend to cause the blade to become trapped. The slit closes up, the material twists and all sorts of weird things happen.

As an example, I milled a long 8 mm wide slot 10 mm deep in a piece of material, about 12 mm from one edge. Lovely cut no issues at all. Until I came to refit the workpiece. The slot had opened up and the outer edge had twisted several mm, preventing the piece from fitting back into the frame of the slide.

It will when the gullets of those fine teeth fill with swarf, keep the fine ones for shallow cuts or thin material.