Hi everyone,

I've a question: What is exactly the difference between a concave and a knob cutter. They both make a hollow wound, to let the wound recover nicely. But why can't you use a concave cutter also as a knob cutter?

Thanks!

howdy Youri,
basically you can use a concave cutter as a knob cutter but i have had times were the concave just wouldn't do the job. its for larger cuts i guess

Okay,

I heard that everyone has a different opinion about this, that's why I was curious to ask it here.

Thanks for your reply

I think, by looking at the blades of both cutters, that the knob cutter scratches out into the wood much deeper. I personally use it to work on a wound, for example to deepen it a bit more than a concave cutter would.

Im very much interested in other opinions; it seems a lot of explanations float around forums etc.

Here you can see the difference between a concave and a knob cutter.
Thanks to Hank for the pictures!

picture 1: the concave cutter
picture 2: the knob cutter

Great! This explains a lot

There is a big difference between the two and using the wrong tool can have a drastic effect (not only aesthetically but health- wise) on your bonsai.

The Concave Branch cutter (Mataeda Hasami) - is used to remove a whole branch at the trunk. The concave cut left behind fills over itself in time leaving little or no scar.(Conclave Cutters come in different sizes)

The Knob cutter (Kobu Kiri Hasami) - leaves an almost spherical cut on the branch thereby allowing it to heal flush with the surface.

Here is a video that shows the difference between the Knob cutter and and Conclave.

Welcome to the forum.

For next time, in general it would be great to not dig up old threads (Although this is a more generic thread with ongoing relevance).