The effect of working temperature and that of subsequeut low-temperature annealing on the hardness and the magnetic properties have been investigated for low carbon mild steel and pure copper.
Specimens were deformed at temperatures between 75°C and 700°C, and then thier hardness and magnetic properties were measured at room temperature. The higher the working temperature on pure copper the less its hardness, while the hardness of mild steel increases at first, reaching maximum at about 250°C and then decreases in accordance with increasing working temperatures. It is because of diffusion of carbon and nitrogen atoms in α-Fe during deformation.
Though the mild steel is hardened by annealing at low temperature after cold working, it is still more hardened through deformation at elevated temperatures.
When specimens are annealed for 30min. at temperatures at 100°C to 700°C after elevated working temperature, the recovering temperature of mild steel and that of copper slightly increase according to working temperatures, and the hardening phenomena generally observed in annealing cold worked mild steel, were not seen when the working temperature was above 250°C.

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In mechanical industry, the most important means to decrease production costs are to save materials and to cut off working hours, as in the case of other manufacturing industries.
On these points, it is one of the most powerfull methods to adopt the thin plate working by so-called presses.
We, firstly, computed the shearing of the thin plate, and we found the factors affected by shearing speed.

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Using a vibrating rod viscometer, the changes in dynamic viscosity and dynamic rigidity of clay slips during casting processes were determined at various deflocculation degrees with the following results.
The fluidity of the slip, and also the hardness of the pieces obtained by casting were found to be improved with the increasing degree of deflocculation α as long as it does not exceed a≅6 Na₂O, 2SiO₂/100g clay, while the extremely high concentration of the deflocculant brought the less fluid slip which produced by casting only the pieces having low hardness values.

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When a metal is lubricated with oil of higher acid value, the wear of the metal becomes greater under the same coefficient of friction, and is nearly proportional to the increment of the acid value of oil due to the wear testing. From this, we understand that the wear of lubricated metals is mainly a phenomenon of corrosion fatigue by the acidity of lubricant. The resistance for wear of various metals consisting of Cu-alloy is found to be influenced by the catalysis of each metals for the oxidation of lubricants. And by the formula introduced, the resistance for wear may be estimated qualitatively.

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In the static test of materials, to get more precisely and easily the relation between load and deformation, we designed a electronic recorder and tested. We made use of differential transformer for strain pick up and of slide wire for load pick-up. Load-recording and strain-recording elements are mutually independent and both have the null balance circuits. This electronic recorder is very helpful to get the stress-strain curves of materials such as steel near the yielding point and cast iron up to fracture.

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