More specific information you can find in the metalurgical reference guide:
The Carbon steels and other its categories have a very sharp-cut line between the tempering treated and nonhardened areas, after the polishing process.
Even with the oils this steels have a hardness of 65 points. On the cooled till -20 degrees technical fuel, this steels have a 70 points hardness. If this kind of steel will be heated till 850 degrees, and after that will be cooled in technical fuel at the -25 degrees, it will keep its properties and could not be destroyed.
After that appears the problem of the correct formulation of thermal coatment. During the heating process (over 800 degrees), the coating looses its contact with the steel, the rate of the linear extentions differs, and as a result the coating is covered with cracks. So it is necessary to choose a special component wich keeps its elasticity properties during the heating process.
Very helpful are the contemporary household chemical goods. A special sealant which is used for ovens and fireplaces and keeps its properties in the temperature from -15 to +1250 degrees is suitable for swords as well. Being applied on the polished blade, this sealant could not be scraped off even after the heating. The steel, covered with this sealing material will be keeped in row condition which allows the peening of the quenched blade that repeats the beinding of the butt without any fissures. That's what we need!
When this "set" of different types of steels is ready, (approx. 1000 layers, one of which is mentioned above), the half-finished product should be hammered.
First the steel must be burned, and after that to set out to the processing till the final shape will be ready. The initial asperities and the inevitable scum are cleared off with the grinding machine or other mechanical equipments. After that, the steel is processed with rough and fine files.
It is very important to scratch off the half-finished item lenghtwise, holding with both hands the file crosswise. In such a way, the edges lines will be firmly shaped and will keep the paralell lines. The file must be of the highest quality and preferable of wide size. When the blade is finished, it must be processed with a grinding sandpaper of different size, from the harshest to the finest one. For this it should be prepared in advance a few hard wood planks, all of the identical size. The grained paper of different roughness is fixed with the nails in circular position on this planks.
The polishing will be executed in the same way as the grinding, but with a less effort, trying not to damage the blades edge. The polishing process will last as long as the blade will seem to be finished.
The next step is the coverage with mastic and the shaping of the quenching layer. The first (protective) hermetic layer (or the high-temperature mastic layer) will be applied on the whole blades area in a very thin layer.
When the protective layer will dry up, on the top of the this layer will be applied the basic protective layer of undiluted mastic. The coating will dry up for 2/3 days and after that it will be quenched.
The blade will be uniformly heated in a special oven at the temperature 850/870 degrees. The blade will be placed in horizontal position, with the blade underneath and with the butt up. After the heating procedure, the blade will be sunked in a vessel with technical fuel untill it will cool down.
A very important factor is the temperature. During 6/8 hours it will be cooled down in the oven at the temperature 150/170C.
The blade will be manually polished and it will be leveled in the same way as before, but by bending method, avoiding any knockings.
The nearly finished blade will be wiped till the clearing with a cloth eventually imbued with a fine diamond paste. And this is the whole procedure.
If your work has not been successful, try again and you will manage.
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