Thread: Metal Core in Razors... True?

I recently saw a wedge razor with a clearly visible core when viewed end on and my guess would be that it would be similar to some knives with a high carbon core and low carbon shell,when the blade is hardened and tempered the low carbon shell is hard enough to resist excessive wear but soft enough to wear easily at the edge exposing the hard core making sharpening easier,i have seen more japanese chef knives made like this than other styles/makes and some are done for costs because of the steel used for the core,some even have a stainless shell to comply with sanitation requirements,there are so many variations on this sort of practise that it's really hard to know exactly what they use and how it's tempered

Originally Posted by Picaro

Hullo, I found this particular crack in my new Dovo just yesterday.

A couple of people have been commenting on rust along the spine of new Dovo's so I got mine out for a look. To the naked eye I found 3 rust spots in a line down the centre of the tip. Under 20x on my loupe, there is indeed a crack from the spine, extending pretty much the depth of the wedge section of the tip. This crack runs almost the full length of the spine, with corrosion starting in several spots.

Being a straights newbie, I've been trying to ascertain if this would be classed as a manufacturing fault, or just something I'm stuck with. I guess an email to the UK wouldnt hurt?

Dovo razors are stamped or drop forged if you prefer the term. Its possibly a section that was not cleaned up fully in the grinding stage.

Hey Picaro, could you post a picture of what is going on with your blade?

Originally Posted by onimaru55

Dovo razors are stamped or drop forged if you prefer the term. Its possibly a section that was not cleaned up fully in the grinding stage.

Drop forging will leave a line where the flashing occurs between the two halves of the forging dies. This is a good choice for possible explanations. But I would have thought that the finishing process would remove most of that.

The other test would be to etch the blade in some cider vinegar. Any differences in the two steels, if welded that way, will be readily apparent.

The only other factor, especially in a monosteel, would be heat treatment stresses. These are small blades and making steel hard is a violent process. Without pictures, this discussion stalls a little.

This is my first attempt at magnified photo's so I hope this is ok.

Yep, that looks like a crack.

Looks symmetrical enough to be from the drop forge rather than a crack but pics can lie.

The rust coming out of it makes me think it is a crack, and that water has wicked into the crack and caused the rust.
I'd start getting happy about sending it back.

It certainly looks like a crack from two metals not fusing together properly. However I would say, due to lack of distortion between the two sides as well as the location of the crack, the two metals fused together were of the same composite.
I don't know how the blade was forged however my observations would support the suggestion that it was caused because of a drop forging process.