Thread: Swedish Carbon Steel

Three months in and I can proficiently shave and strop. I guess I'll get a Norton soon. I find the stropping (hanging and pasted paddle) to be relaxing and rewarding when it shaves well.

Question for you metallurgists: what differenciates Swedish carbon steel from English Sheffield? Does the country of origin set it apart or are the Swedes known for different techniques in cutlery? For a thick beard like mine, which would be an ideal steel that can hold up to my daily torture?

-Rob

In the past, there were few places that were familiar with good methods for producing superior quality steels. They were Sheffield, Solingen, Sweden, Damask e.t.c. The name of the steel coming from these places indicated it's origin, as well as guaranteed it's quality. Sweeden still remains as one of the largest steel industries. Today's steels (alloys) coming from diferent regions are almost same in quality. But the techniques of their grinding, tempering, quenching, ice tempering e.t.c. are diferent at the factories that work with them. So getting DOVO (Sweedish steel) ot TI (Sheffield steel) would be indeed diferent razor, not meaning diferent quality one. DOVO quenches in oil, TI in molten lead. From what I have heard, TI's method produces harder (to hone) edge, and logicaly thinking, since no lead can penetrate, or bind with steel at molecular level, they are tempered to be harder, but more brittle, making them more prone to microchipping?? Never mind (it's almost 3AM here), you don't choose steel, you choose marketing name, and technique of final treatment of the blade.

sorry if this makes little sence,
Nenad.

I'm not sure about razors, but I know with knives, you can usually guarantee the Swedish steels (12C27, etc.) are good, and are usally better than their analysis indicates, because they are so clean, with very few inclusions and impurities. This gives you a more consistent, predictable, and stable heat treat, with more consistent results.

Superfly, I would like to comment on your post on the matter of the heat treating. I'm really not sure, but TI's process sounds very much like austempering in knives. I'd just about bet on it, in fact. In austempering, or marquenching, the steel is taken from hardening temperature straight to tempering temperature, which hardens and tempers the steel in one step. This process also results in the formation of bainite in the steel, rather than austenite (the hardest form of the steel), without the need for additional tempering. In knives, this process is most often accomplished using sophisticated heating equipment and high-temperature salts, but I see no reason it couldn't be done with lead. Because it's so tricky to do, most people don't, relying instead on the tried and true heat-quench-temper method. This process in the TI razors should result in a very hard blade that is also very flexible and tough, rather than brittle. This process is used particularly among the cognoscenti of high-end swords. Just my $.02.

I have a Sweedish razor and the metal is very soft feels quite smooth, but may give way under a dense beard. I imagine the Thiers Issard could hold up better. As for them being "harder" to hone, while it's true that it requires some effort on the hone, it's simply a matter of being less delicate than with most razors. Since trying to hone softly enough is a challenge, in that respect it might be 'easier'.

X

As for "lead hardening" here is an excerpt from the 1924 Machinerys Handbook

"Tempering in a Lead Bath. -- The lead bath is commonly used for heating steel preparatory to tempering, as well as for hardening. The bath is first heated to the temperature at which the steel should be tempered; the pre-heated work is then placed in the bath long enough to acquire this temperature, after which it is removed and cooled. As the melting temperature of pure lead is 618 degrees F., tin is commonly added to it to lower the temperature sufficiently for tempering. Reductions in temperature can be obtained by varying the proportions of lead and tin, as shown by the table, "Temperatures of Lead Bath Alloys".

In this description they are not quenching in lead but instead using the lead to heat the steel to the proper temerature to draw the temper. For those not familiar with heat treatment of steel basically the object to be tempered is heated to a red hot condition then quenched rapidly by plunging it into oil or water. This leaves an extremely hard and brittle piece of steel. The tool or blade is then heated thoroughly to a lower temperature, maybe 350-450 deg and slowly cooled. This "draws" the temper and makes the blade or tool less brittle.

Oddly aluminum works just the opposite. On our aerospace parts (I'm a rocket scientist by day) we heat threat the aluminum to 1000 deg and let it soak for 15 hours. It is then quenched into 150 deg water and comes out dead soft, just the opposite of steel which would have been as hard and brittle as glass. The aluminum parts are then cooked in an oven at 350 deg for a few hours after which they become as hard and strong as aluminum can get, again the opposite of steel which would have became a little softer.

That in a very simplified nutshell is heat treatment and tempering. On the aerospace stuff the details are a secret of course and if I told you I would then have to kill you <g>. I am sure the Thiers- Issard details are a secret too as are Dovos and their own representitives would then have to kill you.

Tony Miller My day job, www.dankoarlington.com

Tony, Joe, thanx for the great info on lead tempering. I didn't kow that there is only one stage in it...

Nenad

My Dovo mammoth Ivory limited is numbered 177, does anyone know how many were made? I understand it is swedish carbon, the blade looks and feels very delicate (when I put Tuf-gide on it) never used it..Yet

Very interesting topic. Does anybody know a bout "Manganese Steel"? I have 2 vintage razors that say Manganese Steel. One sharpens and shaves like a dream, and the other give poor results.

Thanks, Tony.
That may well be how they do it, rather than the austempering or marquenching I'm familiar with. The thing is, if TI does it that way (heating in lead, quenching, tempering) there would seem to be no benefit as to hardness or toughness. Since the lead doesn't bond and add any alloying elements, then it's really just used to heat, much like a forge or fire would be, assuming the quench is then done in water or oil. Lead hardening would then be simply advertising verbiage. I'm certainly not an expert, and I might be missing something, as a lot of people seem to think the TI razors are the sh*t when it comes to edgeholding.

Originally Posted by glrerun

Very interesting topic. Does anybody know a bout "Manganese Steel"? I have 2 vintage razors that say Manganese Steel. One sharpens and shaves like a dream, and the other give poor results.

Again, in knives, that simply means carbon steel. Carbon steel is defined as iron, carbon, and manganese. It's just advertising verbiage to differentiate their product from others, since some use "magnetic steel" or "silver steel"(although silver steel may have something else in it). According to Wayne Goddard's book "The Wonder of Knifemaking", all steels contain manganese. This is an excerpt:

"The most important alloying elements in carbon and carbon alloy steels used for knives are carbon, chromium, and vanadium. All steels contain manganese (Mn). However, manganese is not considered effective as an alloy element until added in an amount over .40 percent. Manganese is in all steels because it is necessary to make the steel sound when first cast into the ingot. Manganese also makes the steel easier to hot roll or forge."