Abstract: In a disc brake a piston is axially slidably mounted within a cylindrical space in a cylinder with an opening in the end of the cylinder communicating with the space. The piston is arranged to move axially through the opening and to press a friction pad into engagement with a disc. The piston is in sliding contact with the surface of the space in the cylinder body. A boot protector covers a boot extending between the inside of the cylinder body and the piston. The boot protector is formed, in part, of a rigid ring body fixed to the opening in the cylinder body in which the piston is housed and of an elastic ring body secured to the inner circumference of the rigid ring body. The boot protector covers the surface of the boot facing toward the disc. The boot covers the surface of the piston disposed in sliding contact with the surface of the cylinder.

Abstract: After the completion of the final heat treatment in the manufacture of austenitic stainless steel material or after the completion of the hot rolling of the material when such final heat treatment is eliminated by a hot finish, the surface of the material which will be contacted with high temperature steam is worked by shot peening. In this way, when the material is used, for example, for a boiler superheater or reheater, the oxidation of the material in high temperature steam can be reduced considerably.

Abstract: A method for manufacturing steel sheet having good cold formability comprising hot rolling steel which contains less than 0.10% C (less than 0.15% annealing for decarburization), less than 0.15% Si, less than 0.25% Mn, 0.4% to 1.5% Cr, less than 0.8% Mo, less than 0.5% Al and unavoidable impurities, cold rolling at a reduction rate of more than 30% and annealing for recrystallization at a temperature above 700.degree. C.

Abstract: Cr-Ni system austenitic heat-resisting steel exhibiting higher heat resistance than that of well-known austenitic stainless steels by means of which an atomic ratio of C being 0.05 to 0.30% to Ti being 0.01 to 0.8% and/or Nb (Ta) being 0.01 to 1.6% is within the range of 1.3 to 7, preferably 3 to 6 and the grain size is within the range of ASTM No. 3 to 8.

Abstract: Creep rupture strength of austenitic heat resisting steel containing chromium and nickel is improved by adding to the steel small amounts of niobium, a niobium-tantalum or a niobium-tantalum-titanium mixture, and maintaining a Nb/C ratio of less than 3.5.

Abstract: An austenitic heat resisting steel exhibiting excellent strength for a long period of time services at an elevated temperature, coexistant-adding 0.02 to 1.0% Nb and 0.02 to 1.9% Zr or 0.02 to 1.0% Nb, 0.02 to 1.0% Zr and 0.02 to 1.0% Ti in addition to usual composition of a stainless steel, simultaneously adjusting the atomic ratio of said(Nb+Zr) or (Nb+Zr+Ti) to C within the range of 0.05 to 1.0, preferably 0.2 to 0.5.