Industrial gearboxes utilize lubricants that generate significant heat and chemical stress. To ensure a “fit-and-forget” installation, our 16x4mm end caps are injection-molded using a high-density Nitrile Butadiene Rubber (NBR) matrix.

This formulation is explicitly engineered to handle continuous exposure to:

• Standard mineral-based gear oils (ISO VG series).

• Petroleum-based greases.

• Operating temperatures up to 100°C (212°F).

The rubber jacket also functions as a permanent vibration dampener, ensuring the plug will not “walk out” of the bore over millions of machine cycles, a common failure point for traditional bare-metal freeze plugs.

From a plant maintenance perspective, the most common cause of end cap failure is improper installation. To ensure the CFKS 16×4 seal remains leak-free, technicians must follow these engineering protocols:

1. Avoid Center Impact: You must never strike the center face of an EC end cap with a hammer or punch. This causes the internal metal skeleton to “dish” or cave inward, which pulls the outer diameter away from the bore wall and creates an immediate leak path.

2. Use a Flat Mandrel: Force must be applied strictly to the extreme outer edge of the seal using a flat-faced sleeve or mandrel.

3. Lubrication: Wiping a light film of system-compatible oil on the rubber OD prior to installation prevents the elastomer from “bunching” or tearing against the housing chamfer during the press-fit operation.