MTAP and Part Tolerances

Elasto Proxy performs design reviews for the products that we custom fabricate. Although we don’t design seals, gaskets, or insulation for our customers, we can review their blueprints, schematics, and computer-aided design (CAD) files. We can also send you PDFs or CAD files of our standard products, which you can then ask us to custom fabricate.

There are two things that Elasto Proxy looks at during a design review: MTAP and part tolerances.  Contact us if you’re ready to discuss your project, or keep reading to learn more.


MTAP, an Elasto Proxy acronym, is a key part of our design review because of its role in compound selection. There are many different types of elastomers, so it’s not enough to just ask for “black rubber”. That’s why we’ll ask you about the media (M), temperature (T), application (A), and pressure (P) that your design will encounter.

  • Media (M) includes everything from fuels, chemicals, and cleaners to freshwater, saltwater, and air. It’s also important to consider whether the contact is intermittent or continuous.
  • Temperature (T) covers normal service temperatures as well as temperature extremes. It also includes thermal aging because high heat can degrade a material’s properties over time.
  • Application (A) starts with how and where your product will be used. It also considers the method of installation, such as with adhesive tapes or metal fasteners.
  • Pressure (P) can cause seal failure in both high-pressure and low-pressure (vacuum) applications. Depending on your design, specifying the operating pressure and working pressure may be critical.

Part Tolerances   

Many of the engineers and designers that Elasto Proxy works with are familiar with part tolerances for metal components. However, rubber has different tolerances than metal – and rubber’s tolerances aren’t as tight. That’s because rubber uses different tooling and is more sensitive to changes in temperature.

If you send us a part drawing with metal tolerances, we’ll let you know that adjustments are necessary. Elasto Proxy can then send you tolerance tables for molded and extruded rubber products that you can apply to your design. These tables are published by the Association for Rubber Products Manufacturers (ARPM), a leading trade organization.

Design Reviews Plus Custom Fabrication

Elasto Proxy doesn’t design rubber products, but we can review your product designs in terms of MTAP and part tolerances. If you’re a designer or an engineer who needs custom-fabricated rubber products, we invite you to contact us.           

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