Thread: W&B's Edges Are Weak (IMHO, of course)

This is fascinating but just starting to get technical beyond my background so I'll throw my 2c in now.

Having recently purged my shaving box and replaced everything with nothing but W&Bs and Filly's (with a nice Engstrom from Sham on top) I have to say the comfort and effectiveness of the W&B are obviously at the top of my list.

I don't use full wedges and refuse to use a full hollow now. I find that the full hollows are "flighty" about cutting my beard with any consistency. No matter who made them or honed them - new or 100 years old. None have held up for more than half a dozen shaves before pulling and some were really never all that smooth even straight from Lynn and Don. To me a full hollow is just a light foil waiting to be battered badly by my whiskers. They battle tough and lose quickly (like the Rockies in the Series)

My W&Bs are not wedges but near wedge - I guess half wedges? My Filly's are just in their own league. The Engstrom is still only one shave into it with me so I can't tell about it yet, but oh that first shave! Sweet!

Back the W&Bs - I have no complaints at all about holding their edge. It may just be that I like tending to my go-to blades once a month or so, but so far, W&B owns half the real estate in my shaving box (well, OK, 4/7ths). I may have to tweak them more often than some of you I guess but honestly, if given a choice between two good shaves from a full hollow then having to sweeten them and a dozen or more from a W&B then I'll go with W&B. Tough beard maybe and maybe I got lucky finding good W&Bs but nothing holds an edge for me longer than W&Bs and Fillys. The Engstrom is in it's probationary period. :-)

Originally Posted by Bart

I don't comprehend that statement.
Taping the spine makes it slightly thicker. The resulting bevel has an angle that is slightly more obtuse. If we would compare the cross-section of both bevels, we would notice that the one cut with the thicker spine has a slightly wider base. Whether the difference of one layer is enough to make the edge more durable in a significant way, is something I highly doubt. (I believe we agree about that).

Yet I measure the bevel angle on every wedge I hone. And I have honed my share of poorly shaving wedges previously honed people that otherwise have no problem putting a good edge on a razor. In several cases the bevel angle was clearly out of range (under 15 or over 19 degrees) Correcting that, by adding, or alternatively not adding, tape always made a pleasant improvement.
I have seen wedges that were honed with at least 3 layers of tape and then convexed on a pasted strop (which only makes the angle even more obtuse), that should have in fact been honed with no, or maximum 1 layer. I have also seen wedges that had bevel angles of 12 degrees, and actually need 3 layers of tape to fall within range.

A bevel angle of 12 degrees easily wrinkles up during the shave. Let's see if I can find that picture back...


It's a "Sheffield Best" wedge, honed with one layer of tape, bevel angle approx. 12 degrees, edge deterioration after one shave. Please take my word for it, that the edge was perfectly straight before that shave.

An edge with a bevel angle of 20 degrees is so uncomfortable that it needs very high keenness not to pull on the whiskers. At the first signs of dulling it starts pulling heavily.



That is exactly my experience. Take the TI Silverwing. Allegedly very hard steel. But shaves like a dream if honed well. But I do not find it particularly having better edge retention that a razor of normal hardness. My beard easily causes microchips in the edge of a very hard razor. I think that's due to brittleness.


+1! I fully agreed.

A final question if I may: Is the purpose of tempering not to bring the RC down to a level that is considered acceptable as being hard enough to be stiff, but not so hard that the steel becomes too brittle for its purpose? So would tempering a hardened alloy that starts out at RC62, not be RC60 or so once it is properly tempered? Or doesn't it work that way?

Best regards,
Bart.

When a blade is hardened it is done so according to a formula for the particular alloy steel being hardened, and the tempering process is likewise dependant on the alloy. I am not sure if it would be a different "plunge" temperature, (a term I just made up because I don't know the proper term for the required temperature of the steel before plunging it into water, oil, or a salt bath), for each alloy or not. I believe there is a formulated hot soak time though. The tempering process is to remove the brittleness of the hardened metal by correcting some of the molecular imperfections and balancing the martensite vs. austenite for the hardest possible edge without micro chipping.

Martensite, named after the German metallurgist Adolf Martens (1850–1914), most commonly refers to a very hard form of steel crystalline structure, but it is also can refer to any crystal structure that is formed by displacive transformation. It includes a class of hard minerals occurring as lath- or plate-shaped crystal grains. When viewed in cross-section, the lenticular (lens-shaped) crystal grains appear acicular (needle-shaped), which is how they are sometimes incorrectly described.

In the 1890s, Martens studied samples of different steels under a microscope, and found that the hardest steels had a regular crystalline structure. He was the first to explain the cause of the widely differing mechanical properties of steels. Martensitic structures have since been found in many other practical materials, including shape memory alloys and transformation-toughened ceramics.

The martensite is formed by rapid cooling (quenching) of austenite which traps carbon atoms that do not have time to diffuse out of the crystal structure. This martensitic reaction begins during cooling when the austenite reaches the martensite start temperature (Ms) and the parent austenite becomes mechanically unstable. At a constant temperature below Ms, a fraction of the parent austenite transforms rapidly, then no further transformation will occur. When the temperature is decreased, more of the austenite transforms to martensite. Finally, when the martensite finish temperature (Mf) is reached, the transformation is complete.

One of the differences between the two phases is that martensite has a body centered tetragonal crystal structure, whereas austenite has a face center cubic (FCC) structure. The transition between these two structures requires very little thermal activation energy because it is a martensitic transformation, which results in the subtle but rapid rearrangement of atomic positions, and has been known to occur even at cryogenic temperatures. Martensite has a lower density than austenite, so that the martensitic transformation results in a relative change of volume.

Martensite is not shown in the equilibrium phase diagram of the iron-carbon system because it is a metastable phase, the kinetic product of rapid cooling of steel containing sufficient carbon. Since chemical processes (the attainment of equilibrium) accelerate at higher temperature, martensite is easily destroyed by the application of heat. This process is called tempering. In some alloys, the effect is reduced by adding elements such as tungsten that interfere with cementite nucleation, but, more often than not, the phenomenon is exploited instead. Since quenching can be difficult to control, many steels are quenched to produce an overabundance of martensite, then tempered to gradually reduce its concentration until the right structure for the intended application is achieved. Too much martensite leaves steel brittle, too little leaves it soft.

Cementite or iron carbide is a chemical compound with the formula Fe3C (or Fe2C:Fe), and an orthorhombic crystal structure. It is a hard, brittle material, normally classified as a ceramic in its pure form, though it is more important in metallurgy.

It forms directly from the melt in the case of white cast iron. In carbon steel, it either forms from austenite during cooling or from martensite during tempering. It mixes with ferrite, the other product of austenite, to form lamellar structures called pearlite and bainite. Much larger lamellae, visible to the naked eye, make up the structure of Damascus steel.

Behavior in Plain-Carbon Steel

As austenite cools, it often transforms into a mixture of ferrite and cementite as the carbon diffuses. Depending on alloy composition and rate of cooling, pearlite may form. If the rate of cooling is very fast, the alloy may experience a large lattice distortion known as martensitic transformation, instead of transforming into ferrite and cementite. In this industrially very important case, the carbon is not allowed to diffuse due to the cooling speed, resulting in a BCT-structure. The result is hard martensite. The rate of cooling determines the relative proportions of these materials and therefore the mechanical properties (e.g., hardness, tensile strength) of the steel. Quenching (to induce martensitic transformation), followed by tempering will transform some of the brittle martensite into tempered martensite. If a low-hardenability steel is quenched, a significant amount of austenite will be retained in the microstructure.

I just like em - so if you have a WB 7/8 meat chopper that you want to sell - just shoot me a pm

(Adding no value what so ever)

Originally Posted by kevint

The stiffness of steel is directly related to thickness. two pieces of equal thickness require the same force to bend R62 or R42.

If you're asking something different it is unclear.

I don't think so. Yet I'm not a specialist.
Unless I'm completely misinformed, which could be, harder steel is less pliable than softer steel. It has a tendency to shatter when bended too far. That's the reason why they tone down the original hardness by tempering it. To make it less brittle/more sturdy. So I think.
Someone like Mike Blue should chime in here.
Edit: I hadn't scrolled down to John's text yet, when I was typing the above. Thanks for that elaborate explanation John, I'm going to give that a thorough read when I get back from work later.

Originally Posted by Bart

I don't think so. Yet I'm not a specialist.
Unless I'm completely misinformed, which could be, harder steel is less pliable than softer steel. It has a tendency to shatter when bended too far. That's the reason why they tone down the original hardness by tempering it. To make it less brittle/more sturdy. So I think.
Someone like Mike Blue should chime in here.
Edit: I hadn't scrolled down to John's text yet, when I was typing the above. Thanks for that elaborate explanation John, I'm going to give that a thorough read when I get back from work later.

You're correct Bart. Harder metal has more wear resistance and softer metal more tensile strength. Harder metal will break sooner if you try to bend it. Softer metal has more shock resistance. Tempering reduces the hardness a bit and is dependent on the tempering temperature and duration. When the metal is quenched after the initial heat treating (in water, oil or air cooled) it has a lot of stress in it due to some metal particles being trapped between the martensite and austenite stages. Over time this will cause the metal to warp and or break.

I've probably shaved with this old WB brute 100 times -- but I discovered years ago that it likes about 5 + 5 strokes on my Carborundum hone just before shaving, then straight to the face. It's always smooth and oddly forgiving, even against the grain. Never a scrape or a scratch. But my overall feeling is that it's soft, I don't have to mistreat any of my other razors like that.