Thread: Soft Steel Razors

Originally Posted by tintin

I would have guessed it to be newer than that.

That is the time frame I was told. Don't get me wrong. I really like the razor. I just was surprised about it getting dull and was wondering if it correlated to the date of manufacture.

I have been told that the Shefield steel was softer steel but i've never noticed a difference in how well they hold a edge. Maybe yours lost it's temper some where along it's life.

Originally Posted by DVW

This one.

If it is as old as you think (I don't know, but given the tail, it could be), it would have been reground. That is also quite a bit of wear on the spine. I think I have heard that on the older blades, the heat treatment would have put the edge at the desired hardness, but further up, not necessarily so. As a means of experimentation, if you've ever scraped rust off a blade with a single edge razor, you'll have noticed the top of the spine and the tang and tail are significantly softer than the face of the blade. It could simply be the case that you have gotten the edge to a portion of the razor that will not hold a shaving edge like the original edge would have.

But that's pure speculation.... Personally, I have found when my edges don't shave like they should and the razor is of reputable make, it's usually my fault, not the razor's.

It may very well be ground down past the temper. The grind is not symmetrical at all from side to side and it does have a lot of wear to it. I re-honed it and will give it another try next week. Right now I have another blade that I need to try out first.

As a side note. The other blade that I have to strop mid-shave is one that I made myself as an experiment. I purposefully heat treated it to a softer state (lower Rockwell value) than I typically would. I was curious how it would perform and feel on the face. It performs just like this old one does. So I'm thinking that it's a heat treat issue. Either this old one is simply worn down past the temper, or it was overheated at some point in it's life while being re-ground.

This is all making me think that when we refer to the old "soft steel" knives, it really has noting to do with the Rockwell hardness of the steel. It must be something else that gives it the "soft" feel.

Originally Posted by DVW

... or it was overheated at some point in it's life while being re-ground.
....

From stuff I've read, old regrinds were done by professionals. Personally, I've never come across a poorly done old regrind. But, one never knows.... (I guess I'm just saying this so people won't be put off needlessly from old reground razors.)

Originally Posted by holli4pirating

I guess I'm just saying this so people won't be put off needlessly from old reground razors.

It's not terrible, and I can still use it. Giving three of four licks on a strop mid-shave is not a deal breaker for me. The strop is already hanging there.

Originally Posted by DVW

It's not terrible, and I can still use it. Giving three of four licks on a strop mid-shave is not a deal breaker for me. The strop is already hanging there.

That's (almost certainly) not because of the regrind, though. From what I can tell, old regrinds weren't for restoration purposes and weren't done by amateurs. Hollow grinding was new technology, and it seems people took their wedges to professionals to have them turned into hollow ground razors not because they were worn out or rusted, but simply because it was possible beneficial (less at the edge =? easier to touch up). I don't have anything to cite; this is just the picture I remember being painted from years of reading on the forum.

Ok, so when we say "soft steel" I think that we are really talking about "face feel" not hardness of the steel. I would love to make some new razors with that old time feel, but that is very subjective. So can we figure out what makes those old razors feel that way? Now I made one before that Glenn said felt very similar. It was coal forged from a car coil spring and had about a 1/8 hollow grind to it (almost a near wedge). So here are my thoughts about what may make them feel that way.

Steel Type:
Who knows what these were actually made of? My guess is that it was a simple carbon steel with .5 to .7 percent carbon, but can someone confirm that? Alloy can also affect grain size, see below.

Rockwell Hardness:
While I don't think this is the key part to face feel, it would be good to have a sampling of hardness from this vintage of razors. It may be enlightening information.

Grain Size:
I would hate to brake a blade of this vintage on purpose, but does anyone have one that is already broken that we can look at? The assumption is that the finer the grain size, the softer the feel would be on the face. 1,000 grit sandpaper certainly feels softer than 100 grit sandpaper, so there is some logic to that thought.

Manufacturing Technique:
I'm told that these old blades were "cast", but what does that really mean? Casting can produce some very high quality metal parts (Ruger revolvers come to mind). Were they sand cast, heat treated and then finish ground? Or were they sand cast and then heated back up and hit with a die (drop forged) before being heat treated and finish ground? That could make a difference. Metal that has only been cast and has not gone through any further refinement process is not known for being very homogeneous or for having a good grain structure. Or were they not really cast at all? Is that just a marketing hype while they were actually drop forged from round stock? Did they run them through any thermal cycles in order to reduce the grain size?

Grind Profile:
These old blades were typically not hollow ground (lack of hollow grinding tools/technology at the time). The two "softest feeling" razors that I have made, have a thicker profile to them. The first being the one mentioned above and the second was forged from an old harrow blade and is ground to a near wedge. It that just a coincidence or is there something to that?

When I hear 'soft steel' in regards to razors, I relate that to how easily it hones. A 1075 steel will hone easier than a 1095 steel at the same rockwell hardness due to less and smaller iron carbides. I suspect that these razors that we know as 'soft steel' are something close to 1075 with a hardness in the mid to high 50s.

Originally Posted by bluesman7

I suspect that these razors that we know as 'soft steel' are something close to 1075 with a hardness in the mid to high 50s.

That is what I would suspect as well. I'm guessing that the coil spring I used was .55-.60 carbon (5160, 9260, 1060, etc...). It behaved as if it had even less carbon than old farm implement steel. While it certainly hardened and took a temper, the sparks were not near as abundant. Razors don't have to be very hard. If someone has a broken razor that was made in the 1700's or early 1800's, I'd love to have it for some testing. Even just the broken off toe would be enough. I could send it off along with a chunk of that coil spring for analysis.