SMC KQ2 Series Brass, Stainless Steel, Polypropylene, Polybutylene Terephthalate Cap for 4 mm Metric

This cap is a pneumatic tubing end closure designed to seal unused or terminated lines in fluid and Air systems. It fits onto 4 mm tubing MADE from nylon or urethane and is manufactured from a selection of materials to suit varied installation requirements. The component incorporates a metric threaded Interface and is intended for applications where a compact, compliant closure is required.

• Constructed from brass, stainless steel and polypropylene for material choice
• Compatible with polybutylene terephthalate for alternative chemical resistance
• RoHS‑compliant tube cap for restricted‑substance conformity
• Metric‑thread pneumatic cap enabling standardised threaded connections
• Pneumatic push‑to‑connect cap 4 mm for fast installation

• Used with nylon and urethane tubing in pneumatic manifolds
• Suitable for sealing supply lines during system maintenance
• Ideal for temporary closure of experimental pneumatic setups
• Can be used for isolating branches in compressed‑air distribution
• Used for end‑cap protection in assembly and storage situations

It accepts 4 mm tube dimensions suited to compatible nylon and urethane tubing.

The construction options include brass, stainless steel, polypropylene and polybutylene terephthalate.

The closure uses a metric threaded Interface to engage standard metric fittings.

The part is RoHS‑compliant, restricting specific hazardous materials.

Models with a -X2 suffix in the Mfr Part No. are copper-free (electroless nickel plated).