Metal belts once were primarily metal bands with the ends manually welded together. Riveted attachments provided some additional function but the belts were most often used in friction drives. Today, precise laser and electron-beam welding replace riveting and imprecise hand welds to produce strong connections in stainless steel, titanium, nickel, and alloys. Special thicknesses range down to 0.002 in. Widths as narrow as 0.027 in. are commercially available. At the other size extreme, belts may be up to 0.030 in. thick and 30 in. wide. Total length ranges from 6 in. on the low end to many feet.
Advantages of metal belts come from their material, usually 300 series stainless steel. Some advantages to metal belts are:
- High strength-to-weight ratio. Thin belts of high tensile-strength alloys have low mass and inertia.
- Good dimensional stability. Because they are almost unstretchable, metal belts are accurate for timing or registration operations.
- Good corrosion resistance. Stainless-steel alloys are inert, nonabsorbent, easily cleaned, and suitable in corrosive environments and in the sterile conveyance of pharmaceuticals.
- High-temperature resistant. Metal belts may be used at elevated temperatures in baking and infrared oven curing installations.
- Conduct heat and electricity. Alloys may be selected for applications requiring electrical conductance, heat transfer, or magnetic properties.
There are three areas of metal-belt applications: friction drives, timing or positioning belts, and drive tapes or metal belts with ends. Friction drives include plain metal belts, coated belts, and perforated belts. Timing and positioning belts are used in place of lead screws, gear trains, articulated arms, and other alternative devices that are usually more complicated, more expensive, or less precise.