Precision Molded Rubber Parts
Services
Rothkopf Differences
TRUSTED
Our customers engage us as a trusted partner to source critical system components made from high-quality precision-molded rubber.
RELIABLE
Our proprietary, fully vetted, reliable network of resources offers unmatched quality, production timeliness, and cost-effective solutions.
SERVICE
Our proactive approach, extensive experience, and customer-first service delivers exceptional value that is unparalleled in the marketplace.
VALUE
Value is more important than cost at Rothkopf. A poorly sourced part at a lower price isn’t always the better choice, it is often a costly one, causing clients delays and potential project failures. The Rothkopf experience is better than a low price; we ensure that we are recommending/sourcing the right part for your project, every time.
Who We Are
Our Story
Rothkopf excels at delivering the right rubber assembly component at the right time and at the right price. These components are critical in our customers’ product performance or operations, and they trust us to provide the highest quality product every time with no margin for error.

Your source for precision molded rubber products
Seals
Seals for a broad range of applications are available, including hydraulic, piston, shaft, wipers, buffers, wear rings, and custom-tooled.
Back-up Rings
Back-up rings work with an O-ring in higher pressure and temperature applications to prevent the O-ring from extruding into the clearance gap between sealing surfaces.
Lathe-Cut
Lathe-Cut rings have a square cross-section profile, perform well in static applications, fit in O-ring grooves, and are interchangeable size-for-size with standard O-rings.
Oil Seals
Oil seals, rotary shaft seals, and V-rings are used to seal in system fluids and lubricants while keeping out dirt and contaminants.
X-Rings
X-Rings have a four-lobed cross-section profile that provides twice the sealing surface of an O-ring, fit in O-ring grooves, and are interchangeable size-for-size with standard O-rings.
U-Cups
U-cups or Lip seals perform well in rod, piston, reciprocating, and some rotary applications. As pressure increases, the “U” shape self-energizes to maintain sealing effectiveness.
Diaphragms
By definition, rubber diaphragms are flexible seals that prevent unwanted transmission of substances between two places. These substances can be liquid, gasses, or solutions. They are characteristically tough and dynamic and essential in many flow control applications.
Cord Stock
Cord stock is O-ring material ready to be cut to create custom size O-rings. There is a large selection of cross-sections available and can be cut to any length you need or in standard put-up lengths.
Gaskets
Our rubber gaskets can seal items, stop vibration, and reduce noise pollution.
Custom Parts
Custom parts can be anything from a unique shaped widget or just a standard style part (O-ring) with a non-standard set of dimensions.
O-Ring Sizing
blog
Our Latest News & Insights
How Attending Industry Events Helps Rothkopf Better Serve Our Customers
The Missouri Association of Manufacturers Trade Show is an annual event that brings together manufacturing professionals from across the state. This year's event took place in Branson, MO, and offered attendees the opportunity to participate in informative breakout...
John Rothkopf’s Legacy
“Don’t write about me, write about someone interesting!”This is what John Rothkopf would have said if we had asked to write about him during his storied life. If you had the pleasure of knowing John, you know the way he would enter a room—calling everyone by name,...
How to Choose the Right O-Ring for Your Needs
O-rings are one of the most versatile and useful components of modern industrial systems, and since their introduction in 1898, they have changed very little, except in what they're made of. From rubber o-rings to ones made of silicone, Teflon, and neoprene, there are...