14 Oct 2016

Plastic Injection Molding – Before You Quote

injection molding ejector pin lines“I have the CAD drawing, what else could they possibly need?”  Does this sound familiar?  Preparing for a plastic injection molding quote may not be as simple as you think.

“…I have the CAD drawing, what else could they possibly need?”

While it is true that a custom plastic injection molder could prepare a quote from just a CAD drawing, or in some cases a hand-drawn two dimensional drawing, you are most likely adding unnecessary expense by not preparing a few essential items beforehand to provide more information for your molder.

5 Essentials For Your Best Plastic Injection Molding Quote

When any plastic injection molder quotes a project, there are a few essentials they look for from a customer:  a drawing, the application or use case, desired material, quantities, and finishing touches.

  1. A Drawing
    Seems pretty basic, right? Still, it’s important to point out that only having a description of the part available can leave a lot to the imagination, and words can be interpreted very differently from person-to-person. The small details you may consider insignificant could lead to significant differences in the tooling/mold cost. That’s why it’s crucial to have at leaset a well-dimensioned hand drawing – many molders will require much more.
  2. Application
    It is important for a plastic injection molding company to understand how your product will be used. Will it be subject to impact? Will it be outside? A good molder will be willing to recommend a material based on the information you provide if you have not already selected one.
  3. Material
    Did you know there are over 80,000 grades of plastic available on the market today? The commonly used grades typically cost $1.00-$5.00/lb., but highly engineered grades can exceed $40/lb.  As mentioned above, it’s important to select a material that has the right properties for your specific product, without over-engineering and adding cost.
  4. Estimated Annual Quantities
    This information is very important, and should be a key part of your marketing plan. Having an estimate of how many parts you expect to order annually will help the molder determine the number of cavities to build into the mold (cavity refers to the number of parts the mold produces each cycle). If your quantities are high, the molder may also recommend using hardened tool steel to prolong the life of the mold.
  5. Any Secondary Operations
    If you’re looking for a one-stop-shop, let them know in advance. Do you want any printing on the part? Does the part need to be assembled? Do you want the molder to package it? Knowing these things up-front may lower your overall costs if the plastic injection molding company views your project as a larger source of income for them.


Plastic Injection Molding – Related Information



  1. Cool article, worth reading…

Post a comment