Shotley Bridge swordmakers

[kronckew]

i found a reference to someone else suggesting extruding rollers to form the blade then heat treating it. which is another skill. heat treating these long thin blades without getting a warp would take real skill, even if you did do a finish grind. not much room for error at all. steel was variable, and temperatures were judged by eye, not electronics. no cnc machines in those days.

[urbanspaceman]

Yes, you're right: keeping it straight during the tempering must have been a major problem.
I have this 1850s court sword from the Coulaux Brothers in Klingenthal which has the most astonishing polished steel blade of the two narrow, one wide hollow variety. I find it difficult to put it down, it is such a marvellous thing to parry about with: stiff enough and sharp enough to penetrate, yet incredibly flexible and light; plus, perfectly balanced. I have a regular two-sided court sword of the same period from Solingen and it doesn't feel anywhere near as comfortable to hold. Plus, I don't know how Klingenthal produced such a brilliant polish to their steel, it looks like it is chrome plated; it's not, is it? I always thought chromium plating was developed in America in the 1920s... but!

[kronckew]

nickel plating has been around a long time: https://www.thomasnet.com/articles/m...ating-history/

found online:

Commercial chrome plating was developed by Fink & Eldridge at Columbia University in 1924, and was based on a 1920 paper by Dr. George J. Sargent. In very simple terms, Sargent discovered that in order to electroplate chromium you need almost exactly 1 part of sulfuric acid to 100 parts of chromic acid. More sulfuric acid or less and it just won't plate. Because of this discovery, the most conventional chromium plating process is still called "the Sargent bath".

also thermal coating of metals with mercury amalgams has been used for millennia. usually by slaves as it tended to kill the artisans using it.

thermal heat treating is hardening the steel by heating it to the temperature where it loses it's nagnetic attraction, then quenching it.

too fast a quench can result in cracking - the dreaded 'ping' or warping. water is usually a no-no, and oil is used. this if done right produces a hard steel, but it's brittle. it must be tempered by reheating it to a much lower temp. (it depends on the type of and composition of the steel) than the hardening required to allow the stresses to work themselves out, allowing it to air cool. (steel can also be 'normalised' or 'annealed' back into a workable softer state by heating it to the non-magnetic temp then cooling it slowly, frequently packing it in insulation and waiting a few days to let it cool.) heating it too high can burn the steel, effectively removing the carbon, and turning it into iron instead of steel.

the hardening rather than the tempering usually produces the unwanted warps. i've heard a primitive blacksmith say if you use a horizontal quenching tank aligned north to south rather than a vertical one it won't warp. not sure how true that is.

the japanese took advantage of this by making their blades almost straight, then differentially hardening them which hardened the edge with a quick cooling, while the spine took longer, and actually self-tempered it all in the same step. it also produced a more noticeable but desired curve. mastering that along with the folding processes and inserting higher carbon steel edges into lower carbon spines was not an easy skill to learn.

p.s. - i've yet to hear them refer to tempering on 'forged in fire' on the history tv channel. probably why they snap so many blades.

[urbanspaceman]

Ah so! Nickel plating eh? Well that would explain the shine. Mind you, I have bought hand-made knives in the USA that are carbon steel and have a superb shine, so maybe it's just the steel well polished. Thank you for all that info, I'm learning so much writing this book.

[Hotspur]

p.s. - i've yet to hear them refer to tempering on 'forged in fire' on the history tv channel. probably why they snap so many blades.

In discussing this with one of the contestants, it has been related to me that the show omits the tempering phase but I have been assured that the makers do indeed temper the blades. Whether deemed a waste of air time or trade secret, that's why.

Of course, the History channel is for entertainment and not any primary source I am aware of. If someone has a question for a smith, ask the smith.

Cheers

GC

[kronckew]

Originally Posted by urbanspaceman

Ah so! Nickel plating eh? Well that would explain the shine. Mind you, I have bought hand-made knives in the USA that are carbon steel and have a superb shine, so maybe it's just the steel well polished. Thank you for all that info, I'm learning so much writing this book.

some people are strongly allergic to nickel, in objects that will be handled, like coins or sword/knife blades, or grips, even zippers, buckles, pins, needles, stainless steel may contain some nickel. the 5 cent US nickel, so called because it is 25% nickel, so is to be avoided if you are allergic.

there is a certain khukri making firm in nepal that produces an amazing mirror polish on their 5150 steel knives. they use a home made polishing disk made from old rags sewn together and a 'magic stone' rouge powder dressing stuck on the wheel with bees wax. the making of the powder and the stone they make it from is a trade secret. (most of the knives they make for the local villagers are left rough or black). the pictures of their 'factory' is scary. OSHA would have a field day. of course period sword factories in the west were not very safe either. before electricity the nepali kamis used a similar wheel turned by hand, with a line wraped around the spindle and pulled alternately one way or the other to get the speed up. no water power either.