CRK Blade Grinds, How Hollow is Each?

[Heirphoto]

I used to know this but just can't remember or find details now.

I know the 21 had a fairly deep hollow and the 25 has much less. The 31 is said to be the same as the 21 as far as blade grind.

So, where does the Inkosi and Umnumzaan fall? Same as the deeper 21 or more shallow like the 25 or do they have something in between?

Thanks

 

[Evany]

I've read that the Inkosi hollow is created on a bigger wheel than the 21's. Comparing my 21 and Inkosi--visually, I have not actually measured them--the Inkosi seems thinner directly behind the edge even though the blade spine is thicker. I have not noticed a difference in cutting performance.

 

[Josh K]

As far as I can remember, the Sebenza is a 10” hollow grind, the Umnumzaan matches it, the Inkosi currently is a 20” hollow grind. I believe the 25 is over 20” on the wheel.

I don’t know about the Mnandi or Impinda. There were several flat ground Sebenzas made a while back as well.

 

[Don M]

The early 25s were 36", this was changed to 20" towards the end of 25 production. Inkosi is 20." The Sebenza and Umnunzaan are 10".

 

[Heirphoto]

Thanks guys. That is sounding familiar now, 10" on 21 and Zaan, 20" on 25 and Inkosi. I don't currently own a Zaan but gave a small Inkosi inbound.

 

[kidcongo]

I have an early production 25, and the “hollow” is almost imperceptible. You need a straight edge and a bright light to see the very slight convex. I think mine is one of the 36” wheel 25’s.

In all honesty, with the thicker stock and the mostly flat grind, I find my 25 drags through materials more than my 21’s or my umnumzaan.