Thread: CPM M4 steel for razors

Originally Posted by jeness

Thats a bit strange, my 1200 DMT plate was worlds faster than a 1k Norton. It left deeper scratches, but it was much faster, especially if I used low pressure with both.

I agree. Grit for Grit comparison, diamonds are much faster. Maybe Bruno was referring to being able to step down then up just as easily and take no more time. Certainly we can agree that diamonds do cut much deeper as well as quickly and therefore the scratches on the cutting edge require more polishing. Still, on difficult steel, it is tough to beat the cutting action of diamonds.

Originally Posted by JohnG10

Your trouble is likely just that you are a beginner, and not the steel or heat treat of your razor. I'm getting 2-3x more shaves between touch-ups now that I have 2 years of experience than I did when I had 3-6 months of experience. I also tried harder razors (including the TI 135 steel). It gave me about a 20-25% more shaves between touch-ups. Not 200-300% more...

Here's some things to try:
Make better lather. Double the amount of soap you are using, and use 1.5 times more water. You should end up with very wet, but thick lather.
Do better prep. Let the lather sit on your face for about 2-3 minutes before shaving. For me, this is the amount of time it takes to strop.
Strop better. Use just enough pressure you can feel the leather's texture. Do 30-40 round-trip laps on the nylon webbing, and 50-60 on latigo leather. Then do 10-15 more very lightly on the leather.
Shave better. Keep the spine 2 spine widths away from your face on WTG, and 1.5 widths away on XTG. Hold the heel 1/2-3/4" lower than the toe, but shave straight up and down (this puts the blade at a slight angle to the path of the shave). Concentrate on using no pressure.
Touch up the razor with 20 laps on a paddle strop with a light dusting of .5 micron paste when you start to get a little irritation (skin feels sensitive after shaving). If you wait longer, you'll start to feel pulling when you shave. If you wait even longer, you'll eventually get a rash-like razor burn.

Good Luck.

I take no offense and appreciate your suggestions but I would like to point out I have three years experience with a straight. I have honed some thirty razors. So let us assume I have gotten lucky with a couple and actually gotten them sharp and polished. The result is the same. I personally cannot believe the nuances of my shave prep makes that much difference on the gross disparity of how many shaves I get with a blade. Or what angle I use for that matter- as long as I am doing my best within physical necessity.

If others chime in agreement with you of course I will accept the truth of it and conscientiously try to change my ways.

I have never received a bona fide "shave ready" blade from a hone master. So maybe I am lacking a true "benchmark" blade. My best success so far is with a Boker Red Injun. Anyone out there want to offer to hone that one for me?

Originally Posted by spacetransient

I agree. Grit for Grit comparison, diamonds are much faster. Maybe Bruno was referring to being able to step down then up just as easily and take no more time. Certainly we can agree that diamonds do cut much deeper as well as quickly and therefore the scratches on the cutting edge require more polishing. Still, on difficult steel, it is tough to beat the cutting action of diamonds.

Did you raise a strong slurry on the 1K? Because that's the situation I was referring to.
Using a 1K with only water and light pressure is indeed a diffeent situation. But with a strong slurry, the 1K really abrades faster than a DMT. At least that has been my observation.

I have an inquiry into Norton concerning composition of 1K. It really requires a ceramic/diamond/ other super-hard stone to get a good slurry out of it. The Chinese 12K stones I use for slurry- was actually getting somewhat ground by the Norton- an impressive feat as hard as they are- and no, I never gave it a try with that one. What do you use Bruno?

I can only personally attest to the 8k DMT vs. the 8k Norton. This is recent because of my foray into the super-steels. The harder and more wear resistant the product, the more diamonds tend to shine in their ability to cut. This is the typical experience of the knife people. I'll get back to you when Norton contacts me. In the meantime

I will keep an open mind on a slurry for the 1K. For the 8k, the Norton is not even close, with the DMT almost 3x as fast (of course there are serious polishing problems because of the depth of the scratches from the 8K DMT and the time/effort it takes to break them in- mine still isn't) - I'll let you know how well the Spyderco 10K (ceramic) deals with that issue on wear resistant steels. Then maybe I can re-visit that Wapi I was rounding off with the Nortons....

Norton 1K, 4K & 8K are Aluminum Oxide/Alumina
This of course says very little except it is quite hard and friable. Aluminum Oxide must be the most prevalent water stone composition but also the most variable due to even slight differences in heating/sintering/structure, impurities or deliberate additives and of course grit.

One "superabrasive" that is yet to mature is cubic boron nitride (CBN). It is already being 'grown' for nano technology frames- so it can get incredibly fine. It is second only to diamond in hardness and while tough will predictably fracture along its crystalline structure, lending the promise of a resistant but friable/renewable abrasive edge for superstones.

Looks like the next wonder abrasive. We will need it if we wish to easily tame the likes of M4.

Sorry for the delay.
I could see how for supersteels, you need to go to diamond.
For regular steels, I find that using a DMT to raise a slurry on the norton 1K gives a very aggressive slurry.
Additionally, there are no deep scratches like from a DMT325.

The coarse diamond for bedding/leveling/slurry is on the way. Thanks for the recommendation.

It is becoming clear to me that the primary consideration for razors over their history has been sharpen-ability. (Assuming the primary influence on shave-ability is blade sharpness).This was not so obvious (to me) before but makes perfectly good, even common sense now that I am dealing with it. One abrasive manufacturer even noted that their aluminum oxide lapping compound was recommended up to an HRC 62 hardness for steel; implying a diminishing return for those honing something harder.

This also implies our razor steel technology was limited by our abrasive technology; not visa versa. Our great-grandfathers could have made "better" steel, but the abrasives were not commonly available to deal with it if they did, combined with the value added labor costs of such a blade would likely make that razor a white elephant. Fortunately for us, other options are present or emerging.

Originally Posted by spacetransient

........One "superabrasive" that is yet to mature is cubic boron nitride (CBN). It is already being 'grown' for nano technology frames- so it can get incredibly fine. It is second only to diamond in hardness and while tough will predictably fracture along its crystalline structure, lending the promise of a resistant but friable/renewable abrasive edge for superstones.

Looks like the next wonder abrasive. We will need it if we wish to easily tame the likes of M4.

I have been using CBN for some time now it is an amazing abrasive. It is not secret that given the opportunity that I will brag on this CBN. I use a nice Asagi Japanese Natural along with nagura to get to the final polishing stage. I use the slurry of the Asagi to finish the blade using traditional methods. I find the Japanese finish very smooth but I prefer a urber sharp edge so I spray a little 0.1 micron CBN on the stone and finish it off using the CBN slurry, then strop. The shaves are superlatively smooth and the edge is very keen.

When starting with JNats I loved the smoothness and some of the reasons touted were that JNats have many different sized particles that made for a non-linear sharpening pattern. CBN if looked at closely also exhibits some of those same qualities plus it cut very quickly. It is wonderful for cutting very hard steels like TI C135 but unlike diamond it leaves a very smooth edge. Before CBN I hated that TI but now it is one of my favorite razors.

I sprayed a little on hard felt and use it like a barbers hone except that I use a stropping motion. Has to be tried to be believed and I have every faith that hard steels will love this stuff.

Later,
Richard

Thanks Richard. Where do you get your CBN?

JENDE: Ken Schwartz CBN Sprays


I use the 0.1 for razors and 0.125 for my wood plane irons.


Take care,
Richard