Tormek Community Forum

In the Shop => Knife Sharpening => Topic started by: ABall on July 24, 2025, 10:47:50 PM

Title: 2 knives, same angle different bevel size.
Post by: ABall on July 24, 2025, 10:47:50 PM
Just curious to know, not the best picture but size wise, the top knife has a 1mm bevel and the bottom one is double that. Is it because the Global on the bottom has a much thicker spine? Both knives have been grinded using eactly the same knife jig and setter.
Title: Re: 2 knives, same angle different bevel size.
Post by: tgbto on July 25, 2025, 08:07:06 AM
It's not so much the spine thickness as it is the "thickness behind the edge".

Of course, knives with a thicker spine will - generally speaking - be thicker close to the edge. And if the knife is twice as wide close to the edge, the bevel will be twice as high.

This is not true with some japanese knives (honesukis for instance), that have a thick spine and a very thin edge.
Title: Re: 2 knives, same angle different bevel size.
Post by: ABall on July 25, 2025, 08:53:01 AM
Quote from: tgbto on July 25, 2025, 08:07:06 AMIt's not so much the spine thickness as it is the "thickness behind the edge".

Of course, knives with a thicker spine will - generally speaking - be thicker close to the edge. And if the knife is twice as wide close to the edge, the bevel will be twice as high.

This is not true with some japanese knives (honesukis for instance), that have a thick spine and a very thin edge.
Ah yes thank you that makes perfect sense.
Title: Re: 2 knives, same angle different bevel size.
Post by: RickKrung on July 25, 2025, 06:13:39 PM

Quote from: tgbto on July 25, 2025, 08:07:06 AMIt's not so much the spine thickness as it is the "thickness behind the edge".

...snip...

And as the same knife is ground with repeated sharpenings, the "thickness behind the edge" begins to increase as the bevel migrates toward the spine.  This would result in much smaller differences, hardly noticeable until it has gone a long way and probably not nearly as much as shown in the OP's photo.