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Fel-Pro®’s LaserWeld™ Stopper Layer Helps Prevent Head Gasket Leaks

Critical Gasket

One of the most important gaskets in your vehicle, MLS (multi-layer steel) head gaskets are designed to seal the firing pressure of the cylinders and seal coolant and engine oil passages. When you need to change the head gaskets in your vehicle, you can count on Fel-Pro® to deliver the application-specific technologies that set the standard for head gaskets.

LaserWeld™ Stopper Layer

Fel-Pro engineers understand that head gaskets are critical to your engine’s performance and are always looking for innovations to improve its head gaskets. One of these innovations is Fel-Pro’s proprietary LaserWeld Stopper Layer that is found on PermaTorque® MLS with LaserWeld and PermaTorque MLS with NextGen Coating head gaskets.

What is the LaserWeld Stopper Layer?

LaserWeld features a unique combustion seal of full-hard stainless steel. This inner layer features a ring with small, evenly spaced “dots” all around each cylinder opening. This stainless-steel ring and the many tiny spot welds made by a precision laser are the Fel-Pro LaserWeld stopper layer.

The LaserWeld stopper layer takes the proven PermaTorque MLS design to the next level. On a traditional MLS head gasket, the embossed beads create the combustion seal. The PermaTorque MLS head gasket with LaserWeld has two combustion seals: the LaserWeld stopper layer acts as the primary combustion seal while the embossed beads act as a secondary combustion seal.


What Does LaserWeld Do?

LaserWeld serves two important functions: aside from creating a more robust combustion seal over traditional MLS head gaskets, it also acts as the primary combustion seal or stopper layer. All Fel-Pro MLS head gaskets are made of multiple layers of stainless steel stamped with embossments that create sealing beads. These embossments act as springs and function best when they are allowed to stay within a certain range of compression between the cylinder head and block. When over-compressed, they cannot fully spring back or “recover,” and leaks can result.


Compression of the multiple stainless-steel layers that make up the gasket is precisely controlled by the LaserWeld stopper layer. The LaserWeld stopper layer provides a positive stop, preventing over-compression and ensuring the sealing embossments maintain maximum recoverability and function as designed.

The LaserWeld stopper layer allows for proper sealing stress between the cylinder head and the block. This vital function also helps to load the cylinder bores more uniformly while ensuring a superior combustion seal. In addition, fatigue life and gasket recovery (in situations where head lift is a factor) are greatly improved.


Application-Specific Design

LaserWeld is not a “one-size-fits-all” approach. Every application that receives a LaserWeld stopper layer goes through specific testing to determine how much additional sealing stress is needed to create an optimal seal. This means dies are designed, manufactured and maintained in-house for each gasket, so there is total control over the manufacturing process.

Fel-Pro PermaTorque MLS head gaskets and PermaTorque MLS with NextGen Coating head gaskets both use LaserWeld when additional sealing stress is needed. If a PermaTorque MLS head gasket does not feature LaserWeld, it simply means the emboss beads provide a reliable seal for that specific application.

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