There are numerous reasons why replacing metal parts with plastic makes sense. Here’s why plastic may be the best option for your parts.

1)decrease piece part prices
 A penny saved is a penny earned. After initial tooling costs are paid, the piece part pricing is usually much less than the same part produced in metal, whether it be a stamping, casting, or a die cast part This cost savings is realized because the injection molding process has faster cycle times (more parts made per machine hour) and these parts are identical from one to the other which eliminates secondary machining.

2) eliminate time-consuming and costly secondary operations.
 Eliminating secondary operations further reduces costs. Plastic material can be colored with color concentrates before molding – eliminating secondary painting operations. Injection molds can be textured or given various levels of polished surfaces before molding.

The costly assembly of several metal stampings or castings fastened together can often be replaced by a single injection molded part incorporating the features of the total assembly. If multiple assemblies are required, the plastic parts can have snap-together features to eliminate any fasteners. Eliminating sub-assembly tooling or fixtures by using injection molded parts can quicken delivery in new product development programs.

3) reduce product weight and improve user ease
One primary advantage of using plastics instead of metals is weight reduction Reducing product weight with plastics gives you more parts per pound of material, significantly reduces shipping costs and improves the end-user’s physical ease in utilizing the product A comparison of the specific gravity values of metals to plastics is shown in the following table:
METALS PLASTICS
Aluminum 2.5 to 2.8 Polycarbonate 1.2 to 1.4
Brass 8.4 to 8.7 Nylon (most types) 1.2 to 1.7
Copper 8.8 Polyethylene .92 to .95
Zinc 6.9 to 7.2 Polypropylene .90 to 1.04
Steels 7.7 to 7.83 ABS 1.02 to 1.4