Cold Rolled Steels (1018, 1045, etc.): Low-cost magnetic materials. Low-moderate strength, corrosion protection recommended.

Alloy Steels (4140, 4340, etc.): Low-to-moderate cost magnetic materials. High strength, corrosion protection optional. 

Non-Magnetic Stainless Steels (316, 304, etc.): Moderate cost. Low strength, corrosion protection not required. Mostly used for hermetic sealed units. 

Magnetic Stainless Steels (416, 430, 17-4PH, etc.): Moderate to high cost, corrosion protection is optional. Low to high strength, depending on the method of heat treatment.

Nickel Super Alloys (Inconel, Monel, Hastelloy, etc.): Very high cost. Very high strength, can be used when corrosion protection is not required.

Beryllium Copper: Very high cost. Very high strength, can be used when corrosion protection is not required. .

Aluminum: Very low cost. Low strength, can be used when corrosion protection is not required.

Plastics (Nylon, Delrin, Teflon, Super Plastics, etc.): Can be used for high speed, low pressure and precise force applications. Low to high cost. Has low to moderate strength and can be used where good corrosion protection is not required.

Ceramics: Use for temperatures up to 250°C (480°F), when corrosion protection is not required.