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CNC Machining vs Injection Molding – Which is the Better Choice?

Whether you’re an engineer looking to create your first prototype or a company who regularly orders high volumes, choosing the right process for your design can be challenging when presented with so many options. The most common methods for plastic fabrication are Injection Molding and CNC Machining. There are several factors you can take into consideration to make your choice easier, such as – quantity, cost, time, and tolerances.

Injection Molding is the process of injecting material into a mold. This is done by melting the stock material and forcing it into mold at high pressure. The part is then allowed to cool in the mold and then is ejected from the mold.

Computer Numerical Control known as CNC Machining is a process that is computer controlled. It starts with a piece of rod or sheet material and then precisely begins by removing the material layers. This process works with all plastic and metal materials, and can achieve precise tolerances with very few limitations.

Quantity: Are you planning to order a few hundred parts or thousands?

When deciding what method of production to use it is important to consider the total quantity you will be purchasing for the life of the product.

Cost: Do You Want The More Cost-effective Option?

CNC Machining can cost quadruple the amount of injection molding, yet it can still be cheaper to machine your plastic components. How? Because the cost to create the initial mold can range anywhere from a couple thousand to a couple hundred thousand dollars depending on the complexity. Then again, if you are planning on ordering thousands of parts per year, and are confident you will not be makings any changes (because each change requires a new mold), injection molding might be the route for you. However, before you decide on a plastic fabrication method make sure you speak with someone about both options. Feel free to contact our experts at (951) 272-9395.

Time: How Soon Do You Need The Parts?

If you have no time to spare CNC machining is going to be your only choice. The reason for this is because injection molding can require up to several months to manufacture a mold depending on the complexity of the design.

Tolerance: How Tight Are The Tolerances?

Most industries require a level of precision that only CNC Machining is capable of achieving. Injection molding only has the ability to reach results within .005 inches of specifications, but cnc machining is able to reach +/- .001” inches of specifications.

The Decision: Determining On a Process!

Deciding on a method can be complicated, and if it can’t be boiled down to quantity, cost, time and tolerance, Tamshell can help you decide which process will work best for you.
Tamshell specializes in CNC Plastic Machining, and can deliver you exceedingly quick parts with tight tolerances for a fair price. Click here to submit a RFQ or call one of our experts at (951) 272-9395.