About SHAMROCK plastics inc.

Know Who We Are

A Woman Owned Company

Shamrock Plastics was founded in 1968 for the purpose of supplying custom vacuum formed parts to the local market. Since that time Shamrock Plastics has expanded and grown, to include pressure forming (an economical alternative to injection molding). This has allowed us to service international OEMs in the off-road, building, environmental industries and developing our own line of Lamplighters by Shamrock holiday yard lamp decorations.

Shamrock has been one hundred percent woman –owned since 1986 by Mary Cay Westphal. Shamrock Plastics is a business dedicated to the highest standards of honesty and integrity. We have distinguished ourselves as top in the industry by our performance, namely: on time delivery of 98% or above and a quality rating of below 50 PPM (Parts per Million).

Call us today and you will find our “phone menu" has not changed, as you will be talking with a friendly member of our family. We possess the flexibility to serve small companies as well as large international corporations. Regardless of your size or needs, our dedicated, experienced and courteous staff is ready to serve you. Shamrock Plastics sets itself apart from other molders by offering you personalized service, competitive pricing, prompt delivery and superior quality products. We combine experience, knowledge and applications expertise to meet the special requirements of each of our customers.
We continually search the marketplace for new, innovative methods and technologies to better serve you, our customer.

We have partnered with Shamrock Plastics for many years and found that they continually search for new materials, technologies or methods that speed up production or take cost out of the tooling.
– Scott & Tom Hermann, Co-Owners of Performance Pattern and Machine


We are frequently contacted by the operations people from Shamrock, researching new, better and more efficient machine technology
Michael Alongi – Sales Manager of MAAC Machinery Corp.