Abstract: A metallic bellows is manufactured by a first step of bulging a straight raw pipe into a primary formed body having formed on a periphery thereof a corrugated bellows section, and a second step of subjecting at least one of crest portions and trough portions of the bellows section of the primary formed body to roll machining by means of a pair of forming rolls.

Abstract: A metallic bellows is manufactured by a first step of bulging a straight raw pipe into a primary formed body having formed on a periphery thereof a corrugated bellows section, and a second step of subjecting at least one of crest portions and trough portions of the bellows section of the primary formed body to roll machining by means of a pair of forming rolls.

Abstract: Modern brake rotors require enhanced resistance to thermal stress in order to withstand vigorous operating conditions. A brake rotor manufactured from (.alpha.+.beta.) titanium alloy will fulfill the thermal stress requirements when an equiaxed grain structure is imposed on the alloy. The equiaxed grains can preferably range from 300 .mu.m to 3 mm in size. The equiaxed grain structure is attained by heat treating the brake rotor at the .beta. phase transformation temperature, followed by quenching. When Ti-6Al-4V titanium alloy is used to form the brake rotor, .beta. phase transformation temperature is 1000.degree. C. the heat treatment temperature range is 986-1200.degree. C. The preferable heat treatment for Ti-6Al-4V alloy is 1050.degree. C. for 2 hours.

Abstract: A brake rotor in which deformation against thermal stress is reduced, thereby preventing a surface layer from being cracked or peeled upon operation of the brake rotor at a high temperature. A titanium alloy is heat-treated at a .beta. phase transformation temperature and is quenched, so that grains of the alloy are equiaxed up to sizes ranging from 300 .mu.m to 4 mm, whereby deformation against thermal stress is significantly improved.

Abstract: A copper series sintered friction material is provided including a foundation constituted by copper alloy powder and containing hard phases and solid lubricant components dispersed uniformly, and exhibits a friction coefficient of 0.3 or more stably without seizure when the sintered friction material frictionally slides against titanium or a titanium alloy in the atmosphere, the foundation containing at least one additive element selected from Zn, Ni, Al, Fe, and Mo.

Abstract: A sintered friction material having excellent high-temperature strength, heat-resistance, abrasion-resistance and .mu. characteristic, and capable of maintaining high friction coefficient stably is provided. The sintered friction material contains a foundation of titanium and/or titanium alloy powder, a solid lubricant and a fiber of hard material. The sintered friction material having the foundation of titanium and/or titanium alloy powder as the base is lined and joined onto a holder plate to form a friction pad suitable for use with a brake rotor made of titanium or titanium alloy.

Abstract: A heat-resistant, wear-resistant and high-strength Al-Si alloy, wherein(A) 3 to 5% by weight based on the total amount of the alloy of alumina particles having a maximum particle diameter of 30 .mu.m or less and an average particle diameter of 10 .mu.m or less and having shaped with no sharp edge and(B) 0.5 to 3% by weight based on the total amount of the alloy of graphite particles having a maximum particle diameter of 10 .mu.m or less as measured on a cross section of the Al-Si alloy structureare dispersed in a matrix consisting essentially of ingredients for an Al-Si alloy and having primary Si crystals, the sizes of the primary Si crystals being not larger than 10 .mu.m.

Abstract: A V-pulley is adapted for a continuously variable transmission which uses a chain belt composed of a plurality of chain blocks connected in its longitudinal direction, and a pair of V-pulleys operatively connected to each other through the chain belt. The V-pulley comprises a pair of conical pulley faces that the chain belt contacts, each of which is provided with a rough surface and a combination pattern of abrasion-prone and abrasion-resistant sections alternatively arranged at intervals shorter than the contact length and width of each chain block.

Abstract: A wheel for vehicles comprising a wheel body consisting of a rim portion, spoke portions and a hub portion, and two bearings disposed at the left and right of the hub portion. The wheel body is integrally made of a fiber-reinforced resin and is composed of symmetrical left and right halved bodies. Each spoke portion has a square hollow cross section and is formed including matching flanges of the respective spoke portions of the halved bodies. The flanges are joined together by a bonding agent and mechanical fasteners. The rim portions has a circumferential synthetic resin film coating and a cylindrical projection extending radially inwardly with an air valve fitting hole therethrough.

Abstract: This invention relates to a valve seat material for an internal combustion engine, which comprises a sintered ferrous alloy having the composition:______________________________________ chromium 5-15 percent by weight cobalt 5-20 nickel 2-8 tungsten 2-10 molybdenum 0.2-12 carbon 0.2-2 the remainder being iron except for usual impuri- -ties and trace elements, ______________________________________And having a porosity of 5-25%. This alloy can also contain lead and a low melting point glass capable of showing a lubricating property at a low temperature.