Gaskets vs. Seals: What's the Difference and Which Do You Need?
If you've ever sourced components for a sealing application and found yourself wondering about the difference between gaskets vs. seals, you're not alone. The two terms are used interchangeably all the time, but they're not the same thing, and specifying the wrong one can mean leaks, failures, and rework. The good news: once you understand what sets them apart, selecting the right extrusion profile becomes a lot more straightforward.
At Vip Rubber & Plastic, we've been manufacturing custom rubber and plastic extrusions for over 65 years. We produce both gasket and seal profiles in a wide range of configurations, and we work with manufacturers every day who need help deciding which option fits their application. Here's what you should know.
What's the Difference Between Gaskets and Seals?
The difference between gaskets and seals comes down to one key distinction: how and where they create a barrier.
A gasket is a static sealing component. It sits between two mating surfaces (think flanges, panels, or covers) and prevents fluid, gas, or debris from passing through when those surfaces are compressed together. Gaskets are cut or molded to fit specific mating geometries and are designed for applications where the mating surfaces don't move relative to each other during operation.
A seal is typically used where there's movement involved, or where a component needs to compress against a single surface or channel to close a gap. Extruded seals are designed to deform and recover. A bulb seal, for instance, compresses when a door closes and springs back when it opens. They're found in doors, windows, hatches, enclosures, and anywhere a dynamic or adjustable closing interface is needed.
In practical terms: if the two surfaces are bolted together and stay put, you likely need a gasket. If one surface moves, like a door, lid, or panel, you likely need a seal.
Rubber Seal Extrusion Profiles
Rubber is the go-to material for sealing applications that demand flexibility, compression recovery, and weather resistance. Our rubber extrusions include a broad range of seal profiles built for industrial, commercial, and OEM applications.
Bulb T Seals
The bulb T seal combines the compressible bulb with a T-shaped base that slots into a channel or groove, holding the seal in place without adhesive. Ideal for applications where the seal needs to stay anchored while still allowing door or panel movement.
Double Bulb Seals
When a single bulb isn't enough contact, the double bulb seal provides two points of compression in one profile. This design increases sealing surface area and can compensate for uneven gaps or surfaces that aren't perfectly parallel.
E Seals
Our extruded rubber E seals get their name from their cross-sectional shape. The multiple lips of an E seal create redundant sealing contact points, which is useful in applications where a single lip may not maintain consistent pressure across the full closure.
H Seals
The extruded rubber H seal is designed to connect two panels or sections while sealing the joint between them. The H-shaped channel accepts the edges of both panels, making it a practical choice for joining two surfaces with a weathertight interface.
Window Seals
Our window seals are extruded specifically for glazing and window frame applications. They compress to create a weathertight fit between glass and frame, preventing air and water infiltration while accommodating the thermal expansion common in window assemblies.
Custom Seals
Not every application fits a standard profile. Our custom seal capabilities let us engineer and extrude a profile to your exact specifications - cross-section geometry, durometer, material compound, and tolerances. If you have a unique interface or closing geometry, we can build around it.
Rubber Gasket Profiles
Punched Gaskets
For flat static sealing applications, our punched gaskets are die-cut from extruded rubber profiles or sheet stock to match specific flange or mating surface geometries. This process allows for precise sizing and consistent compression characteristics across every piece.
Punched gaskets are used wherever two rigid surfaces need a static seal - pipe flanges, access covers, junction boxes, and equipment housings are common examples.
Plastic Seal Extrusion Profiles
Plastic extrusions offer different performance characteristics than rubber, and in certain applications, they're the better choice. Vinyl and other thermoplastic materials resist UV degradation, maintain their shape under long-term compression, and can be co-extruded with other materials for added functionality. Our plastic extrusion profiles include a full range of seal configurations.
Plastic Bulb Seals
Our plastic round bulb seals bring the same hollow-bulb compression design to thermoplastic materials. These work well in door and window systems where UV exposure, chemical resistance, or specific color matching is required.
Half-Round Bulb Seals
The half-round bulb seal profile provides a lower-profile sealing option where space is tight. The flat base bonds or sits flush against the mounting surface, while the rounded top creates the sealing contact.
Push-In Bulb Seals
Push-in bulb seals feature a retention base that snaps into a channel or slot, eliminating the need for adhesive installation. This speeds up assembly and allows for easier field replacement when seals wear.
Push-In Bulb Seals with Fins
A variation on the push-in design, push-in bulb seals with fins add flexible fins to the retention base that grip channel walls more aggressively. This improves retention in applications where the seal may be subject to pull-out force or vibration.
Push-In Back Side Seals
Our push-in back side seals are designed to seal the back edge of a panel or door within a channel. The push-in base locks into position while the sealing surface contacts the back of the adjacent structure.
Vinyl Glazing Seals
Vinyl glazing seals are extruded specifically for glass retention and weathersealing in window and door frames. The vinyl compound resists UV and moisture, and the profile geometry grips the glass edge while maintaining a weathertight perimeter seal.
Bottom Drip Seals
Bottom drip seals are installed at the base of doors to prevent water from driving under the bottom edge. The profile deflects to clear the threshold surface during door operation and returns to sealing position when the door is closed.
Co-Extruded Bottom Drip Seals
Our co-extruded bottom drip seals combine two materials in a single extrusion pass. A rigid carrier provides structural support and mounting stability, while a softer sealing compound provides the contact surface. The result is better durability with the sealing performance of a flexible material.
Angled T-Seals
Angled T-seals mount into a slot and angle outward to contact a closing surface. The angled profile compensates for misalignment between the frame and the mating panel, making it a practical choice for applications where tight manufacturing tolerances are difficult to maintain.
Top Load Seals
Top load seals are inserted from above into an open channel and lock in place under the weight and pressure of the application. Common in framing systems and window assemblies where side-load installation isn't possible.
Custom Extrusion Manufacturing With 65+ Years of Experience
Vip Rubber & Plastic has manufactured custom rubber and plastic extrusions since 1957. As a family business, we've built long-term relationships with material suppliers that let us keep pricing competitive without sacrificing material quality or lead times.
We can produce standard profiles from the list above, or engineer entirely new profiles when your application calls for it. Both rubber and plastic extrusions are manufactured in-house, and we work directly with engineers and procurement teams to keep the process straightforward from spec to delivery.
Ready to talk through your application? Request a quote and one of our team members will follow up to discuss your requirements.