Thread: how much spine wear is to much

i found a union cutlery SPIKE razor this weekend but passed on it because the spine wear was more than i like. i like the grind of the blade (the one pictured in the library section says half hollow) i thought it was more wedgy than that but anyway, would spine wear of 3/32 to 1/8 flat make this type of grind too warn to make useable?

This type of question is always a judgment call that you have to make

Weighing all this when you do

1. Size of the blade, ie a 7/8 or 8/8 with 1/8" spine wear isn't as bad as a 4/8 or 5/8 with 1/8" spine wear
2. Is the spine wear even
3. Is the size of the razor consistent with the amount of spine wear
4. Is the edge is line with the spine
5. Overall condition or the razor

Weigh all that against the price

And you are correct the Spikes are closer to a 3/4 wedge than a 1/2 hollow IMHO anyway

Can't really add much to what Gssixgun said, other than that the flatter the spine looks, the more worn it is.

Here's an example of bad hone wear:


The spine looks very flat and it isn't even. Because the hone wear isn't even, the size of the bevel changes according to the shape of the spine. I'm not sure what the effects of an uneven bevel though.

Just do the math on it.

You can do basic trigonometry to get an idea of what bevel angle your going to get.

In order to do this and get a fairly accurate angle it's easier to work in metric, And you have to split the razor into 2 right angles triangles.



Work in 2 triangles.

So take the total spine width, Then divide that width by 2 to get your 2 triangles. {a}

Then measure the Hypotenuse, This is the distance from the widest point on the spine (usually the top of the spine wear) to the tip of the edge. {c}

Using this calculator Right-Angled Triangle Calculator

The red letters above are correct for the calculator note case sensitive.

The resultant angle {A} Will be half of your total bevel angle. So multiply this figure by 2.


You can either use trial and error to get the correct spine width for and angle of 17-22 degrees.

Or you can work the math the other way to get a ball park figure for spine width by using your desired bevel and Hypotenuse.


To do this

Bevel = 18 therefore angle {A} = 9
Hypotenuse {c}

Hit calculate and it will give you {a} Remember you have to double this to get your total spine width.

Assuming the soundness of the spine - being parallel w/ the bevel - wear isn't really an issue. It can be a PITA to hone because of all the metal that has to move to hone it. But if you don't have a phobia against tape - who cares? I don't mean to imply I don't have any vanities, but in terms of suitability for shaving - this one doesn't register.