Forged Vs Stock Removal?
A common question that is asked regarding knife making is, “what is the difference between forged and stock removal methods?” The following are the two main methodologies. The first is stock removal – removing stock from a piece of steel. I’ve compared this to a forged (San Mai) – forge welding three pieces of steel into one. This creates a hard steel core with a soft steel outer skin.
The Stock Removal Knife Making Method
You now have a piece of steel ready for heat treatment.
Time taken: 30-45min
Margin for error: Very little.
Pre-designed Stock Removal for Knife Making
If you wish to speed up production, you can also pre-design a profile using CAD software. Then employ a third party to cut out blanks via a water jet cutter.
Hand Forged San Mai Method
This example using hammer and anvil to forge a San Mai (3 Layer) construction.
Time taken: 2-3hrs – Depending on length of blade.
Margin for error: High
Possible faults that could arise:
- De lamination of the dissimilar metals
- Cutting steel out of alignment within the billet causing soft steel to be exposed along and cutting edge.
- Overheating the billet which will dissolve an excessive about carbon into the softer mild steel (excessive carbon migration)
- A flaw in the weld which can only be detected during grinding post heat-treatment.
Which method produces the best blade?
Ultimately, if both blades have 52100 (knife steel) at the cutting edge then performance will be similar or identical – providing both blades were heat treated identically and correctly.
The difference lies in the processes, the aesthetic, and a preference for traditional hands on methods. Any piece made by hand – a term thrown around rather loosely these days – will produce individuality via slight imperfections. I have also learned so much more about the craft by using traditional methods. Hammer blows move steel differently with the slightest adjustment to the hammer head and steel temperature, carving tools move cleanly through timber once you learn how to read the grain direction, and flexibility in sharpening is achieved once you learn how to use stones freehand.
I also like a quiet workshop. Obviously that’s not always possible, but knife making also has hours of quiet processes that can be further lengthened by using hand tools.
One sure advantage of a San Mai blade is thinning behind the edge, thinning will eventually be required when the knife has been in service and sharpened regularly. Due to the soft steel behind the cutting edge thinning time is greatly reduced.
Hopefully after reading this article you will have a better understanding of the various methods in knife making.