Mechanical Parts Suppliers
US
McMaster-Carr - A leading US supplier of raw materials and mechanical components.
Stock Drive Products - Huge range of mechanical components.
Servo City - Motors, gears, belts, wheels, drivers and much more.
Australia
Small Parts - Screws, nuts, bearings, materials, and tons of small hobby parts.
Netherlands
RVS Paleis - Stainless steel screws, nuts, drill bits & taps