Thread: anybody know the ratio to figure spine thickness compared to blade width?

Originally Posted by superfly

This is a section from the German book “Das Rasiermesser” (The razor) has been written in 1939 and was published by Der Messerschmied Verlag.
Nenad

Is there a chance of purchasing a translated copy of that book Nenad?

Originally Posted by superfly

There is, and it is the 3.5. It is fixed number, and it is used to retain the sharpening angle at the edge of the razor.

THis can't be right, as can easily be demonstrated with different 5/8, one with a thick spine and one with a thin one.

A while back we had a thread where I demonstrated how to determine the bevel angle of a razor. It's typically about 11 degrees. Using that value, the ratio of the blade width to the spine would be a around 4:1. However you will find that this angle varies with the blade design, as does the thickness of the spine for a a particular width blade.

Originally Posted by superfly

This is a section from the German book “Das Rasiermesser” (The razor) has been written in 1939 and was published by Der Messerschmied Verlag. It goes into detail about production techniques, geometry, and it also addresses the increasing competition with safety razors and electric shavers.

"One of those rules is the to conserve the thickness of the back, which should be the blade width divided by 3,5. The hollow grinder divides the blade in two halfes: the upper part is hollow, the lower part is a biconvex belly. The biconvex part consists of the edge, the thinning and the belly. The biconcave part of sole, the hollowing, the back and the stabilizing piece. The sole is the thin transition between the belly and the hollow part."

From the descriptio it's clear that this is only a particular shape of blade. Only one shape (full hollow?) has that belly.

Tony Miller gave you some examples, and I invite you to compare the spine thickness of a Begischer Lowe with one of the Dovos in the low price range that has the same blade width.

Joe,
I notice it also in the various Dovo models. The tortoise shell one I sell has quite a heavy spine as oppsoed to the basic one in my kits yet both are 5/8.

My Thiers- Issard frame back has a 1/4" thick spine and it is a 6/8.

Tony

The 3.5 to 1 ratio is mentioned in that text on the razorcentral website

http://www.en.nassrasur.com/razorcentral/index.html

but it is not a hard and fast rule as Joe Lerch has shown.

Originally Posted by randydance062449

The 3.5 to 1 ratio is mentioned in that text on the razorcentral website

http://www.en.nassrasur.com/razorcentral/index.html

but it is not a hard and fast rule as Joe Lerch has shown.

Thanks Randy, I think I'm going to take a while and peruse that site. Info like that is very much appreciated!

Originally Posted by randydance062449

The 3.5 to 1 ratio is mentioned in that text on the razorcentral website

http://www.en.nassrasur.com/razorcentral/index.html

but it is not a hard and fast rule as Joe Lerch has shown.

If you look at the different grinds at that site you'll notice that only the full hollow has a belly.

Originally Posted by Korndog

Is there a chance of purchasing a translated copy of that book Nenad?

Larry, I have no idea, but i think it is unavailable . I found that info on nassrasur website, maybe someone there has a copy of that book? The guy's name that runs that place is Arthur E. Boon.

http://www.en.nassrasur.com/razorcentral/index.html

ref:

Reichszinnungsverband des Buchsenmacher- und Messerschmiedehandwerks. Das Rasiermesser, sein Werdegang, seine Pflege. Verlag der Messerschmiede, 1939. Out of print.

Originally Posted by superfly

Larry, I have no idea, but i think it is unavailable . I found that info on nassrasur website, maybe someone there has a copy of that book? The guy's name that runs that place is Arthur E. Boon.

http://www.en.nassrasur.com/razorcentral/index.html

ref:

Reichszinnungsverband des Buchsenmacher- und Messerschmiedehandwerks. Das Rasiermesser, sein Werdegang, seine Pflege. Verlag der Messerschmiede, 1939. Out of print.

I'm not sure as to how accessable Mr. Boon would be but Razor Central once had it's own site and then disappeared for a while and now it's being hosted by NassRasur.
NassRasur, is owned and operated by Norbert Schick (he's the guy in the DOVO video) and Norber also specialises in seeking out rare and out of print books Soooo..... one would only need to contact Norbert to see if there is any chance of getting a copy of "Das Rasiermesser" because if anyone know's I'd bet he does. If you havent looked around NassRasur, you should. He has a great collection of info there including some neat books for sale. Alas, no mention of a copy of Das Rasiermesser