Thread: CPM M4 steel for razors

M4 will likely make a good blade. What metal are you using for the other? Looking forward to the test results.

I am not a honemiester, but I would assume for a harder steel a harder hone would be called for.

Jeff

spacetransient,

I have a few knives in CPM M4, and they are a right sod to bevel - diamonds are defintely a friend here !

Once the edge is there, they are superb performers.

I have always hankered after a razor made with one of the high vanadium CPM 'steels'

However, are the properties of these types of 'steel' really needed in a razor ?

Have fun !

Best regards

Russ

Thanks for the interest and comments. Many of you echo my own thought processes in issuing the challenge to Doug who was so kind as to take on this unfamiliar steel in a public forum.
First, I have become a razor collector like many of you, looking for a better shave and the nuances that make for great personal handling characteristics. I have a good idea now of what those characteristics are for me, a Fu Mustache owner. And like many of you here who would rather not deal with the cost and/or inconvenience of constantly honing/stropping, I was looking for that "vorpal" blade like all good Razorphiles! My beard is not thick but must be wiry because it eats blades like sandpaper. I suspect I may not be unusual in that regard. You tell me.
So I read up on the steel offerings that might improve on the tried and true Swedish, German, American and British blades. I was specifically impressed with particle metallurgy, micro-fine iron and alloys mixed and melted together in a way as to in theory create smaller carbides (largely the "wear" resistant factor in steel) lending a more refined and less "toothy" blade that would hold that edge and once obtained, would be no more of a chore to hone or strop back again. The M4 was among the leading candidates, if not the clear favorite in the extreme knife cutting competitions which as we all know are impressive but not necessarily indicative of the best blade steel for a face shaving razor. I kept that in mind when I spoke with my blade-smith.
Second; without question the grinding and tempering of the blade, and all the other nuances of skilled craftsmanship that go into it are at least as important as the steel composition. A man who knows his steel and how to execute the blade can make a good if not great blade out of almost any serious blade material. But why not shoot for a leg up? Give him a great steel to work with and even if it is unfamiliar, see what happens? Why is M4 great? A nice balance of fine grain, toughness, and hardness and that helps to translate into the ability to achieve and hold a fine edge. My primary concern was how "toothy" such a true razor edge would become.
We can go more into the details of metallurgy if there is an interest; I am a novice but have absorbed allot from the knife forums and makers. Frankly, the knife blade people savor these types of discussions and I am wondering since the new blade market is so much more limited than the vintage for razors, maybe we have a bias towards the vintage and are not as interested in exploring new refinements? Admittedly it is somewhat costly yet some of these desirable vintage blades regularly go for over $300 dollars. I was convinced if I could put the same kind of money into a custom blade I would for sure get the ergonomics I was looking for (I get to specify that) and possibly receive a better cutting blade that relieved me of some, not all, of the common maintenance issues as well. Also, as a utilitarian looking for my own personal vorpal blade, I wanted something I could just order and stop searching for as the flavor of the month. After some 40 or 50 razors, I still need to grind down the blades to the shape I like them, while still being dissatisfied in many cases with how refined the edge becomes and how long I can keep it that way with relative ease. The quest has been worthwhile yet many a blade has been reduced in value as a collectible as a result.
BTW- toughness and strength is not normally an issue with razors unless we pry or drop them! But if it did not matter at all then most of us could be happy with ceramic blades- just don't bump them on the sink or faucet!!
Steel is all about the trade-offs of characteristics. Ergonomics is about shape and balance. Craftsmanship is about the nuances in blending steel, scale, ergonomics and aesthetics with pragmatic results. Otherwise it's just art for art's sake.

The biggest difference between tools and razors comes down to the FEEL not the sharpness (toughness is just not a factor in razors)
My favorite saying is and has been for some time "Razors differ from every other tool for one simple reason , they have to feel smooth when you drag them across your face" not once but every single morning...

I would like to hone it !!! and test shave it

Interesting points above. For me the most important thing is the comfort of the shave. Due to the delicate nature of a razors edge, I think all factors are important particularly when it comes to honing and shaving with the razor. We have had several blade smiths come over to the razor world and this is a very nice thing, but I think some realize quickly the differences in the instruments. The points being made regarding vintage and new steels could go on with fans of both forever, which they probably will complete with the hate that we see in other places (sowwy), but these debates and the efforts of those to introduce new and old steels and techniques actually are very helpful. Unfortunately, what we see sometimes is the hype around trying something from a sales perspective. The bottom line really should be let's try this metal or technique and see what happens and report purely on that. How does that razor hone up? How does it shave? These two questions will continue to be the real bottom line and not that the razor CAN shave, but is it a comfortable shave. The only thing I can say so far from having tried some of these miracle steels is that not only are they hard which can be problematic, but they tend to feel grainy on the hones and uncomfortable to use when shaving even though they will shave. I hope you guys who know metals, will continue to play around with new stuff as most of us continue to search for that ULTIMATE edge. I have seen several razor makers play with CPM 154 and ATS 34 both of which shave nicely, go back to using more traditional tool steels. I'm sure a degree of personal preference comes into play here too. The only thing I would ask is that the proclamations of greatness come after the testing and use instead of before.

Have fun.

Agreed, the proof is in the shave. I will get back the two blades this week and begin my own personalized tests and report back the pro's & con's of each as well as the blade-smiths experience crafting the M4. I will also try to get both HRC hardness tested. My bino-scope only goes up to maybe 100x (long story on the guess) so that will be of interest to me as well.
In the meantime I was hoping for and you all were generous enough with your time to give me some feedback as I really enjoy experimenting and getting the feedback from thoughts and experiences each of you can bring. Here is a picture of my best handling blade which also gets me one of my more comfortable shaves. I bought this with a chipped point so I did not have to feel guilty grinding to my liking or spending a lot of extra money to get it. This too is far from ideal as I prefer a heavier and somewhat wider blade, about 3/4"-13/16" and a bit stiffer/less hollow as well. A blade like that has to be made to order or ground from vintage, and wrecking a nice vintage blade is not my recipe for fun- it is a loss to history. So now the pursuit of steel for my ideal shape- one that can be reasonably worked on by any good blade-smith; not limited to the greatest or proprietary methods like an Iwasaki or the difficulty and expense of obtaining one to my specifications- though that would be a dream machine for sure!
Three other great steels for cutlery come to mind as well not usually seen in straight razors. One, closer to old school: "Hitachi White Paper" and maybe closer to the Iwasaki as well. The next would be the Sandvik line of cutlery/razor steel mentioned by Bruno: 12c27 or 13c26 or 14c28N; the first would arguably be the finest grained, the second a little harder but less stain resistant, the third more stain resistant and about as hard but so far proprietary to Kershaw Knives that helped develop it with the 19c27 being equal or superior to the previous in stain resistance, toughness and hardness but not as fine a grain and not recommended by Sandvik as razor stock. The major disadvantage of those "strip" steels is the thickness and flatness- they are literally shipped in coils with a maximum of 0.130", thinner than my liking at the spine/tang for a finished razor much less the raw flat. But the knife people are wanting it so maybe Sandvik will come around. Lastly for me will be something along the 19c27 lines, but maybe even a bit finer and made from heavier stock- the SB1 or Niolox steel made by Lohmann in Germany. Not easy to get here but as I understand it is available in heavier thicknesses. I have an email out to that end.
I will report back when I have done some test drives next week.

The test begins. Here are the three blades I will rotate until each has exhausted it's sharpness and is replaced in rotation with the one or two other blades still holding sufficient edge for my tolerance level. They will each be stropped with linen and latigo before each use only. No other honing or touch ups will be used as I follow my normal shaving routine. Only three blades will be rotated for my shaving until the "experiment" is complete. Each represents a different type of steel. Doug's standard is a low alloy carbon steel. The Spartacus I believe is a low alloy carbon (please chime in if you know the content) which is used as a reference/gauge against the other two. The one on the top left being the M4 super-steel.
The M4 blade arrived a bit less polished than the standard model. It was obvious there was much more difficulty in finishing this one- as the M4 'didn't seem to know it was being polished' as I recall Doug's explanation. This is why bead blasting is so common with these super wear resistant blades. I finished all three as close as I could do it with a microscope view to keep the comparison fair. Basically I used the popular Chinese finish stone as required and Chrome-Ox with a little 0.5 micron diamond spritzer. The M4 never really polished out but I decided not to go to extremes and just let the normal shaving and stropping take its course. The fine edge of the M4 was the most toothy and chippy of the three and I was just glad to get it smooth while quite sharp. All three achieved approximately the same level of sharpness from what I could tell.
Again the purpose of this is two fold: 1) to get the style of razor I want- and these blades are the closest I have had in that regard and 2) to get them in the "best" steel I could - the one with the most acceptable trade-offs in edge holding, honing difficulty/edge maintenance, and most importantly, how good a shave the blade and my efforts could bring after the smith's labor was complete.
I took my first drive today but will make that review after all three get their initial shave impression. Be back in a couple days.

Would you mind using paragraphs with a blank line in between? That would make your information much easier to read.
Nice work btw.

Thanks Bruno for the suggestion. My inexperience is showing.

All three razors have been test driven. The two from Doug have the weight and proportions I was looking for and I am very pleased (54 & 56 grams) while the quite nimble Spartacus weighs in at 46 grams. All three are very close in sharpness. The Spartacus is probably the least hard, followed by the M4 with Doug's standard low alloy carbon steel probably the hardest. When I have an opportunity I will get them checked on the HRC scale.

I could not tell the difference between the M4 and the more standard carbon steel in feel or closeness. All three are less than perfect in sharpness and polish, with a bit of pull while cutting. If that is mostly due to polish they might improve with a couple more shaves and stropping's. The Thiers-Issard felt the sharpest, probably due to the more acute edge geometry, but actually gave me more difficulty cutting at my chin than the heavier blades. Despite that it felt a little smoother, perhaps due to being a little less hardened and more responsive to the polishing and stropping than the other two.

Normally I would have gone back to more polishing or fine honing as required to get the best shave I could out of each blade. I chose instead to judge readiness by the 63x view on my microscope alone for the sake of simplicity and comparability; not only to help remove bias but keep the edge from getting rounded by more polishing/stropping which lends a softer feel but less shaves. Part of this process is to keep a running count of acceptable shaves and then the time necessary to return the blade to an equal or superior edge. I will get back when there is a noticeable difference from these initial impressions as the rotation proceeds.

Thanks again for everyone's comments and patience.

Originally Posted by spacetransient

When I have an opportunity I will get them checked on the HRC scale.

Don't you run the risk of damaging a finished razor by doing that ?