Are those grain lines or grind lines?!
Those lines are under the coatings on most of the Busse family knives.
They are only on the "flat" sides of the knife. They are not on the grind areas.
I am pretty sure that Busse (Swamp and Scrapyard) all use the same (apparently) high tech equipment to heat treat and test for hardness.
However, I am sure the treatment process for the different steels (INFI, SR101 & SR77) all very a little.
I have two theories that are based on other information I have read ... or ... I just made up the information and I will claim I created the theory based on information I have read because I can't remember....
Theory 1:
Busse (and kin) have a machine that tests the whole length of the blade for proper hardness. The machine marks the blade in a zig-zag pattern as it is testing for hardness. Maybe the blade is fed through such a machine (??).
Maybe you have seen the hardness test mark on a Puma knife. Puma does a hardness test near the guard area of their knives. The test makes a little divot hole.
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Theory 2:
The marks are from a machine that is part of the Transverse Wave Tempering process. I can't go into any more theory about this as it is top secret.
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The marks a bugger to get out if you are removing the coatings from Busse, Swamp Rat or Scrapyard knives.
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