Custom Plastic Shims

Higher quality, lower costs, and one-week shipments on most orders. Drop-shipped to your construction site.

True, Plumb, Square, and Level with Quick Turnaround Times

Choosing Custom Plastic Shims



Choose a strong, lightweight, and environmentally resistant plastic. You can even choose UV-stabilized materials. Most custom plastic shims are made of HIPS or ABS. HDPE costs less when thicker material is required.



The three most common thicknesses are 1/16", 1/8", and 1/4", and going up to 2". Common shim dimensions range from as small as 2" x 2" to as large as 10" x 10". Smaller and larger shims are available upon request.



Use them with any type of masonry, including cinder blocks and bricks. They're a lot better than those old-fashioned wooden shims in normal construction, whether it's masonry or bricks and sticks. These custom plastic shims are a great choice for doors, windows, retaining walls, and many other building and construction projects.



Just set them on the block, or slide and lock them into place. Custom plastic shims with a hole or slot fit over a bolt or threaded rod so that you can screw down and anchor them in place. No matter how you place them, these custom shims are build to take heavy loads.

Action Plastics machines custom plastic shims instead of molding them. This means you can easily change sizes without paying for more tooling or delay.  

Plastic Shim Types & Thicknesses

U-Shaped Shims

Horseshoe or U-Shaped

Strong, lightweight and designed to fit around bolts and anchors.

U-Shaped Shims

Center Hole

Ideal for spacing, aligning, and solving leveling problems.

Key Slot

Shaped to snap in place with a restricted slot to keep them for sliding off.

Flat Plate Shims

Flat Plate

Built to handle heavy loads., often permanently, and with slip-resistance.




Horseshoe Shims


Horseshoe Shims


Thicker sizes are available upon request. We also offer custom packaging and labeling.

Custom Plastic Shims Case Study

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Plastic Machining vs. Injection Molding

Standard shims aren't custom shims, and all custom plastic shims aren't made the same way.

Most standard plastic shims are injection molded. Molten plastic is injected into the cavity of a die, the material cools, the die opens, and the parts are removed. Then the die closes and the process begins again. It sounds simple, but it can get expensive. You’re not just paying for steel tooling. You’re paying for a different tool every time you need a different-sized shim.

Consider this example. A customer asked an injection molder for a 1/8″ x 3″ x 4″ sized shim. Then the customer needed shims in three other sizes: 1/8″ x 3-1/2″ x 4″,  1/4″ x 3″ x 4″, and 1/8″ x 3″ x 4-1/2″ instead.  The injection molder couldn’t use the original tool and quoted three new dies for a total cost of over $100,000. With tooling expenses like that, it was time to look for other options.

So, the customer began contacting manufacturers of custom plastic shims. Because these companies used injection molding, they were limited to the dies in their inventory – unless they outsourced the work to Action Plastics. As the leader in plastic machining, we’re only limited by the thickness of the material. And we don’t need to make a mold so machine your custom plastic shims. When you work with us, you’ll save time and money.

Ready to get started? Let us know what you need.