Mechanical parts are generally categorized into subcategories of different mechanical parts and components. The additional categories of mechanical parts include bearings, general mechanical components, hydraulic and pneumatic, linear motion, power transmission and valves and fittings. In the world of mechanical parts and fabrication services, bearings consist of all types of bearing such as ball bearings, bearing accessory, needle bearing, pillow block bearing, rod end bearings, roller bearings, slewing bearings, sliding bearings, special bearings as well as other bearings. General mechanical components, out of all mechanical parts and fabrication services, comprise flanges, gaskets, moulds, seals, shafts and other mechanical parts as well. Hydraulic & pneumatic entails cylinders, hydraulic cylinders, hydraulic parts, pneumatic cylinders, pneumatic parts, and pumps whereas linear motion is comprised of ball screws, linear bearings and linear guides in addition. Power transmission entails many more parts and components e.g. gearboxes, gears, pulleys, shaft couplings, speed reducers, sprockets, sprockets, transmission chains, universal joints, and worms and other power transmission parts. In the world of mechanical parts and fabrication services, valves & fittings are composed of ball valves, butterfly valves, check valves, diaphragm valves, gate valves, manual valves, needle valves, pipe fittings, solenoid valves, vacuum valves, and valve parts, and different types of valves as well.