Thread: Grinding thoughts

Originally Posted by Arcanum

Hey there guys,

Great info here, thanks for that.

Is 'annealed steel' the type of steel to buy, or is it a process you put it through before grinding?

I'm hoping to make my own razors eventually and am just trying to learn as much as i can, at the moment I know very little.

Generally speaking....Annealed steel is steel that has been softened. The term applies to all types of steel.
The steel I use is 1095 steel. A high carbon unalloyed steel. The process to anneal this steel is to heat it to over the critical temp, 1475 F.,
and then promptly put it in a insulated box so that it cools very slowly. There is a better way but a kiln is needed for that method.
Generally, when you purchase the steel you will be told if it is cold rolled annealed or hot rolled and not annealed.

Originally Posted by Del1r1um

thanks for the additions guys, really good stuff

here is an animation I made to show how I go about grinding a smiling blade (the razor pictured isn't really that great of an example, but the path is very close I think)

I hope this gif works... we'll see

It looks like the gif didn't work in the post, so here is a link to it in the wiki
Smile Grinding

I know it isn't perfect, but the basic idea is there I suppose

I sure wish I had your skill with graphics!

If you fellas don't mind, I'm going to be compiling all of your tips along with the stuff here and making a razor grinding page on the wiki. I really appreciate your input, and by all means keep it coming!

Originally Posted by randydance062449

I sure wish I had your skill with graphics!

Ha... parlor tricks I tell you

Originally Posted by randydance062449

Generally speaking....Annealed steel is steel that has been softened. The term applies to all types of steel.
The steel I use is 1095 steel. A high carbon unalloyed steel. The process to anneal this steel is to heat it to over the critical temp, 1475 F.,
and then promptly put it in a insulated box so that it cools very slowly. There is a better way but a kiln is needed for that method.
Generally, when you purchase the steel you will be told if it is cold rolled annealed or hot rolled and not annealed.

I'm penning frantic notes as I read all the posts I'm going through, old fashioned I know but a little easier when it comes to quick referencing.
Now I know what kind of steel I'll eventually be looking for I won't make as much of a plonker of myself when asking. Thanks a lot mate.

Originally Posted by Arcanum

I'm penning frantic notes as I read all the posts I'm going through, old fashioned I know but a little easier when it comes to quick referencing.
Now I know what kind of steel I'll eventually be looking for I won't make as much of a plonker of myself when asking. Thanks a lot mate.

An old file is made from high carbon, unalloyed steel and makes for some good practice material. The downside is that it must first be annealed and the teeth must be ground off. Be sure to start with a thick, 1/4" or better, file or else be willing to settle for a smaller razor.

I just added parts of this (and a bit more) to the wiki.
Here is the link Hollow Grinding Please feel free to add helpful hints as you can...Thanks everyone, and please keep the info coming.

That is really cool! Thanks a bunch for putting that in the Wiki.
Just a couple more comments ........

1. I start with a 60 grit belt which is fine for the profiling of the razor blank but I find that it leaves very deep scratch marks on the hollow grinding of the blade that are difficult to get out later. I may start using 80 grit for the hollow grinding to reduce the deep scratches that have to be worked out.

2. Shape/width of the face of the wheel..... Most wheels are flat and 2" wide, that gives more contact with the steel at one time but also requires us to compensate by moving the blade laterally to even up the hollow grind.
There are 3 other options
A. Use a narrower wheel... this is the best option for a blade with a
curved spine/edge ( smiling blade shape)
B. Use a wheel that is crowned in the center in profile
C. Use a wheel that is half round in profile

3. A 3" wide flat faced wheel is of no use.... it would leave deep scratch marks because the blade is stationary. The blade must be moved to blend out the scratch pattern from the abrasive belt.

4. Speed of the belt( not the contact wheel).... for profiling/shaping the razor blank a high speed is desirable. Most of the grinders come with a 4" drive wheel ( not the contact wheel). assuming a 1750 rpm motor that will drive the belt at 4 x 3.146 = 12.584"/12 = 1 ft per revolution or 1750 surface feet per minute of belt speed. That is a good speed for grinding the hollow of the blade. But for profiling you need to double that speed unless you have a lot of patience. Finish grinding is best done at 1/2 that speed or even less ( less is better) such as 400 sfpm.

I have used a grinder that had a 10" drive wheel. It is great for profiling, but cannot be used for hollow grinding or finish grinding. The steel simply gets hot so very fast.

Thats my brain dump for the morning,

Originally Posted by randydance062449

That is really cool! Thanks a bunch for putting that in the Wiki.
Just a couple more comments ........

Thats my brain dump for the morning,

Thanks Randy, Just added your comments to the page

Great Thread Guys!!

Would you say that a 4-6 inch wheel on a belt sander is best for full hollows and that an 8 inch wheel would be best for 1/4 hollows on larger (7/8) blades?

Thanks,

Lynn

i use 50 and 180 grit belts adn then gators (they are worth every cent you ppay for them )
+s for the gator belts are all grits are the same thickness of belt (made for CNC grinders) there is no belt splice bump you can round the corners of the belt to soften the edge and you can dresss them like a bench grinder stone to refresh the bit of the belt or to reflatten it
-s is you cant run them wet and there not cheap but if you dont mess them up they last pertnear forever

i use 10 inch for wedge 6 inch for part hollow and 2 inch for full hollow grinds