Harman makes caps, plugs, and grips in any shape, any size, and any color. The differences between the three are very simple, but why each are selected and used can be more complicated :

  • Plastic Molded Caps push or thread on the outside of a product as a protective cover or seal.
  • Plastic Molded Plugs push or thread inside the part to protect or seal.
  • Plastic Molded Grips are like a cap, they fit on the outside of the product, but are typically longer than most caps and usually part of the finished product.


Whether you need caps, plugs, or grips there are many ways they can be used both for product finishing and product protection.

Product finishing

Plastic molded caps, plugs, and grips become part of your finished product providing a clean and completed look and providing ongoing protection.

Plastic molded Caps are found on many consumer and B2B products adding a touch of color to the final product, providing the final finish when capping a tube or pipe, or even covering a rough edge for protection as well as for the sake of aesthetics. 

At Harman, we make plastic molded caps for thousands of tools and appliances including a ”hubcap” for lawnmowers, tube ends for bird feeders, protective covers for wire shelving units, and countless other applications, many of which are specifically customized to the product. If you need to properly finish your product, Harman can create a custom molded cap in any size, shape or color.

Plastic molded Grips are like a long cap that slide over the outside surface of a product. You probably touch grips every day without thinking about where they come from. 

Molded grips help finish both consumer and B2B products like hand tools or power tools, they provide a place to hold on to exercise equipment, and sturdy grips are used for rugged outdoor machines like pumps and latch handles on trailers. 

At Harman you can have your plastic grips printed to provide instructions for your users if desired. We have clients that print their names, logos, and instructions (up for off, down for on) onto the grips.

Chances are very good that if you’ve used a major branded tool that has a double color grip, if you’ve pulled the lever on a trailer or pump, been thankful for the soft padded grip on a shovel or rake, scooped a fish out of the water with your fishing net, or worked out at the gym or on your own home exercise equipment, you’ve probably been holding on to a plastic molded grip made at Harman.

Plastic molded Plugs are used in finished products in multiple ways. A plug may close the top of metal tube or it might be used to cover rough edges at the end of that tube or pipe. 

If you have ridden a motorcycle or bicycle there’s probably a plastic molded plug at the end of the handlebars. If you’ve used a small trailer to haul dirt or hay, or carry your bikes or motorcycles, there’s probably a plug that covers the end of the metal frame of the trailer. There are countless applications where plugs are used to hold liquids in, or keep liquids out, and provide a beautiful finish while doing those jobs.

Though you may not have noticed in the past, there are millions of products around the world that have caps, grips, and plugs that are used to finish products and provide a complete, polished look while adding functionality.

Next time you walk through your local hardware store or sports store, try counting the products with plastic molded grips, caps and plugs that you see. I think you might be surprised!

Keep out dirt or moisture

Another application for caps, plugs and grips is to keep dirt and moisture away from the product and provide protection. Dirt or moisture can ruin electrical systems, create corrosion on products, or generally wreak havoc for things that need to stay clean and dry.

Caps and plugs can create an airtight seal to help keep your product clean, moisture, and dust/dirt free to avoid contamination or damage both during the manufacturing process, during storage, shipping and when used on a normal day to day basis. 

Protect your product during the finishing process

Whether you are painting, powder coating, anodizing or electroplating, you may need to provide protection while your product is being finished. Typically caps that are used purely for product protection during the finishing product are made from either vinyl or silicone. Both have distinct advantages depending on your use case.

  • Vinyl caps and Vinyl plugs are inexpensive and are often used for wet painting or for general protection. Because vinyl caps are so cost effective they are often considered to be disposable so there’s no need to be careful about the cap or plug when those in the warehouse are removing them. Vinyl plugs have a heat tolerance up to about 400 degrees Fahrenheit, so they are perfect for general protection, wet painting, and other product protection applications that don’t require high temperatures.
  • Silicone caps and Silicone plugs provide protection up to about 600 degrees Fahrenheit so silicone is the logical choice for high temperature finishing processes. For those with powder coating applications, anodizing, or other high temperature applications, silicone plugs are often the perfect product protection solution. Another benefit of silicone is that the plugs and caps are highly flexible and often reusable so, though they may cost a bit more than vinyl caps or plugs initially, over the course of time silicone may be a less expensive option.

Protection during storage and shipping

The worst thing that can happen to your product is to get damaged while sitting in the warehouse waiting to be shipped or damaged while shipping to the next destination. Your warehouse workers, truckers and shippers might not be as gentle as you are, so caps and plugs are often needed to assure that your product arrives undamaged.

Whether capping or plugging a pipe, tube, or exposed part, protecting a corner from getting dinged, covering sensitive electronics, or making sure that threads aren’t damaged, caps and plugs provide protection against dents, scratches, dirt, and other problems that arise during storage and shipping. 

As mentioned above, the cost of vinyl caps is typically very small, and Harman can make product protection in any shape, size or color, so there’s a cost-effective protection available no matter the size or shape of your product.

Protect exposed threads

We have heard of entire assembly lines being shut down because of damaged threads on products when they arrived. Because the products were damaged they were unusable and the plant shut down while new product was ordered, shipped and received. 

In this “just in time” inventory environment, protecting exposed threads with a cap or a plug is imperative to keep production moving. A couple of cents spent on a vinyl cap or plug to protect exposed threads can save you thousands of dollars in lost productivity when as your products get to the assembly line or end-user in perfect condition.

Almost every day at Harman we have the opportunity to work with a customer to create a custom cap, grip or plug designed and manufactured specifically for their unique product. Whether that’s a non-phthalate grip for a leading toy manufacturer in a custom shade of pink, a flat “tophat” shaped cap with UV protection to cover solar equipment in the field, or a silicone plug that must withstand 600 degrees Fahrenheit in a powder coating oven, Harman provides caps, grips, and plugs in any shape, any size, and any color.

How can we help you? 

You can get a free sample of anything on our website. Please contact or call us at 248-651-4477 to discuss your needs with a product expert to find out Harman can help you with a custom plastic molded cap, plug or grip.