fiveNot all gaskets go into brand new applications straight off the production line. There are many gaskets used across the aftermarket, in service operations and in engine rebuilding. Do the same rules and considerations apply to the seal points and gaskets in service applications as they do in OEM manufacturing?

We have put together a list of considerations for those working with gaskets in situations where a gasket is being replaced.

Things to Remember

1. Flange surfaces will change.

Over time and repeated heat cycles, flange surfaces can warp and become distorted, become pitted or corroded, or otherwise become less than ideal. When replacing a gasket, you’ll either need to spend both time and money machining the flanges back to their original state, or use a gasket that can compensate for the irregularities now present. Often, thicker, more compressible gaskets are used in service applications to not only save cost in flange prep, but to make up for material lost in the flange resurfacing process.

2. Replacement products vary greatly.

Service parts are available across an entire spectrum of price and quality. Customers typically are in control of choosing the cost and quality of the parts used in the repair. Parts are available from OEM quality (or better) down to low cost/low quality choices. How long do you want the gasket to last?

3. There are alternatives to the OEM gasket.

While marketing experts will want you to believe that you can only replace a gasket with the same OEM gasket, there are actually quite a few OEM-quality replacements on the market. You can usually save some money and sometimes get better performance.

4. Multiple factors to consider

There are many factors to consider in the process of replacing gaskets. One of which is the installation process itself. What is the torque? What is the sequence? What is the process? Should I include a sealant? Should I retorque it? Is it possible it might be upside down? Are the flanges clean and prepped? The answers to these questions will ultimately help you to settle on the proper replacement gasket, as well as ensure it will perform as expected in your application.

5. Materials / Construction

Have you explored and considered the various material choices for service applications? Which one is best? There are often different constructions of gaskets. Some are single-layer materials, some are embossed metal, some are composite laminates. Which is best? Often, the composite designs are the best choice in replacement parts as they best compensate for the factors mentioned throughout this post.

Plenty of Options

Although there are a few extra considerations when choosing a gasket or gasket material for a service application, you may actually find that you have a little more latitude. There are materials out there that have characteristics that excel in these markets. Talk to your trusted gasket material supplier to figure out which materials will be best suited for your application.

What differences do you find between sealing OEM and service applications? If you are interested in subscribing to Sealed-In’s blog posts, email

Metal Tech offers the HT 337, which works well in many service applications.