- Automation & ControlView all 1,843 products
- AC Drives
- PLC & I/O Cards
- Industrial Communications
- Vibration Monitoring
- Automation Accessories
- Controllers & Data Acquisition
- Isolator & Barrier
- CCTV & Security
- Safety Switches & Guard Locking
- Encoders
- HMI Displays
- Industrial Computers
- Servo Drives
- Motor Soft Starters
- Pneumatic Cylinders
- Machine Vision
- Automation Software
- Robotics
Brand: SMC
SMC KK4P-02MS S Coupler Plug R1/4 Male Thread
Description
The plug half of a KK series quick coupler
KK4P-02MS is the plug half of an SMC KK series S coupler in size 4. It screws into a tool, a hose end or a fixture and pushes into the matching socket KK4S-02MS to make an airtight, one-touch connection. The plug is the side that moves, so it is usually fitted on the tool or the portable equipment.
The code reads KK (series), 4 (the 1/4 body size), P (plug), 02 (R1/4 port), M (male thread) and S (with sealant on the thread). The plug has no check valve; the check valve is in the socket.
Technical specifications
| Parameter | Specification |
|---|---|
| Series / type | KK S coupler, plug, body size 4 |
| Fluid | Air, water (deionized water is not recommended) |
| Operating pressure range | 0 to 1 MPa for the KK4 size |
| Proof pressure | 1.5 MPa |
| Ambient and fluid temperature | -5 to 60 deg C for air; 5 to 40 deg C for water (no freezing) |
| Connection thread | R1/4 male, with sealant |
| Plug and socket connection | One-touch connection and release |
| Sleeve lock mechanism | Manual locking type (socket sleeve) |
| Effective area | 39 mm2 for the coupled KK4P-02MS and KK4S-02MS pair |
| Plating | Electroless nickel plated, copper-free and fluorine-free application |
Matching the plug and the socket
A plug and a socket belong together only in the same series and size. KK4P-02MS connects to KK4S-02MS and to the other size 4 sockets of the series, such as those with female thread or one-touch tube fittings. The thread of each half is chosen for the line it joins, so the plug can have a different thread or tube connection than the socket.
The catalogue lists effective areas for the sizes: 3.8 mm2 for the M5 size, 20 mm2 for 1/8, 39 mm2 for 1/4 and 82 mm2 for 1/2. These are the areas of the coupled pairs.
Use and limits
Couplers are suitable for air and for general water, but the catalogue states that the sockets are not guaranteed for zero leakage, and they are not recommended for deionized water because it can attack the material. Keep the pressure within 0 to 1 MPa for this size and keep the temperature in the range given. Do not use the coupler to carry a load; the hose should be supported so that the plug does not bear its weight.
Wind sealant tape carefully, or use the version with sealant (S) already on the thread, to avoid particles entering the line. Before ordering, check that the thread on your tool or hose adapter is a male R1/4, since the female and tube versions use other codes.
Related SMC products: SMC AN20-02 Resin Silencer R1/4 Male Thread, SMC AS2201F-01-06 Speed Controller 6 mm Tube, R1/8, SMC KQ2H06-01S One-touch Male Connector 6 mm, R1/8, SMC ZH07BS-06-06 Vacuum Ejector Box Type 0.7 mm, 6 mm Tube, SMC TU0604BU-20 Polyurethane Tubing 6 mm Blue, 20 m and SMC ZH10DS-06-06-08 Vacuum Ejector Body Ported 1.0 mm.
Documents and quotation
The SMC KK catalogue PDF below has the how-to-order page, specifications, effective areas and dimension tables. Please confirm body size, thread and connection type before ordering. Related parts are listed under Automation Accessories. Seven Star LLC is an independent supplier and quotes the exact code on request.
KK4P-02MS Pair Data & Materials
| Item | KK4 series pair (KK4P-02MS + KK4S-02MS) |
|---|---|
| Effective area (connected) | 39 mm² |
| Socket body outside diameter | Ø28.0 mm |
| Socket mass | 44.1 g |
| Flow direction | Flow is possible from the plug side or the socket side |
| Plug stem material | C3604 brass, electroless nickel plated |
| Seal against the plug | NBR plug O-ring, fitted in the socket |
| Socket check valve O-ring | FKM |
| Sleeve cover (socket) | Weather resistant NBR, spare part KK4S-P01 |
How the KK4P-02MS Plug Connects
The KK series uses a connection method without steel balls. When the KK4P-02MS stem is pushed straight into a KK4 socket, a stainless steel 304 chuck inside the socket grips the stem and the sleeve locks it. As the stem goes in, it pushes the socket check valve open, so air or water can flow. Because the KK design has no valve spring in the flow path and no balls narrowing the bore, the pair keeps a large effective area for its size. When the socket sleeve is pulled back, the plug is released and the socket valve closes. The plug itself has no valve, so the hose or tool side of the plug vents when it is disconnected.
The SMC catalogue shows that the force needed to insert the plug rises with the charging pressure in the socket line. For the KK4 series this force is moderate at low pressure and increases towards 1 MPa, so it is easier and safer to connect when the pressure is low.
Selection & Ordering Guide
- Thread: KK4P-02MS has an R 1/4 male thread with sealant. Other size 4 plugs include R 1/8 (KK4P-01MS), R 3/8 (KK4P-03MS) and R 1/2 (KK4P-04MS) male threads, a female thread version, a hose nipple and One-touch tube fittings.
- Socket: any KK4 socket, for example KK4S-02MS. SMC states that the KKH series is available only as sockets and that KK series plugs are used with them, so KK4P-02MS also fits the shock-resistant KKH4S-02MS.
- Different sizes cannot be connected: select the plug and socket of the same series and size. A plug of another size or another make can cause leakage, damage or disconnection.
Our team can help confirm the correct ordering code for the KK4P-02MS and the socket that suits your line.
Installation & Maintenance
- Hold the plug firmly when connecting. Push it straight into the socket and keep away from the sleeve until it has locked; then pull gently to check it is held.
- Hold the plug firmly when releasing it, because the pressure on the plug side can push it out.
- Wipe off any foreign matter on the plug stem before inserting it, so that the plug O-ring in the socket is not damaged.
- Do not use the coupler as a stop valve that needs zero leakage; a small leakage is allowed during operation.
- Tighten fittings with sealant to the proper torque and do not over-tighten.
Typical Applications in Oman & the GCC
Pneumatic hand tools, blow guns, spray equipment, tyre inflation lines, portable test rigs, and quick-change jigs in workshops, fabrication plants, oil and gas service yards and maintenance shops across Oman and the GCC.
Why Source the KK4P-02MS from Seven Star LLC
Seven Star LLC supplies SMC S couplers, fittings and pneumatic components across Oman and the GCC. Request a quote for KK4P-02MS plugs together with the matching sockets.
Datasheets & Documents
- Catalogue SMC KK S coupler catalogue (manufacturer PDF) Download
Reviews (0)
About brand
SMC is the Japanese specialist in pneumatic automation: air preparation units, solenoid valves, cylinders, fittings, process valves and sensors. Yoshiyuki Takada founded the company in Tokyo on 27 April 1959 as Shoketsu Kinzoku Kogyo, which means Sintered Metal Corporation, and its first products were sintered metal filters. SMC Corporation is headquartered in Tokyo and listed on the Tokyo Stock Exchange, and its products are used on machines and instrument air lines across the world.
Seven Star LLC, an independent supplier in Oman, lists SMC AW series filter regulators (AW20 and AW40) and the VX2 series direct-operated 2-port solenoid valve, and sources other SMC parts by full part number.
SMC company profile
| Founded | 27 April 1959, Tokyo, Japan, as Shoketsu Kinzoku Kogyo (Sintered Metal Corporation) |
|---|---|
| Founder | Yoshiyuki Takada (1928–2024) |
| First products | Sintered metal filters; pneumatic air line equipment from 1961 |
| Headquarters | Tokyo, Japan |
| Ownership | SMC Corporation, a public company listed on the Tokyo Stock Exchange |
| Product families | AF/AR/AW modular air preparation, VT/VQ/SY solenoid valves, VX/VXZ 2-port valves, air cylinders and rotary actuators, fittings and tubing, pressure and flow switches, vacuum equipment |
Milestones
- 1959: Shoketsu Kinzoku Kogyo is founded in Tokyo on 27 April and starts making sintered metal filters.
- 1961: Pneumatic air line equipment is added.
- 1964: Automatic control equipment becomes part of the business.
- 1967: The first overseas operation starts, with a stake in an Australian company.
- 1970: SMC begins making air cylinders.
SMC series listed on this page
The AW is a combined filter and pressure regulator in SMC's modular air preparation line. The body size is in the name: AW20 is the smaller unit and AW40 the larger, and the digits after the dash give the port size. A part number such as AW40-04-A therefore describes body size, port and options in one string. The VX2 is a direct-operated two-port solenoid valve for shutting off air, water, oil or steam, depending on the body and seal materials chosen.
SMC products we list
Ordering SMC parts: what we need
Give the complete SMC part number from the label, including thread prefix, options and the final suffix letter. For AW units state gauge, drain type and bracket if you need them. For VX2 valves send coil voltage, port size, orifice, body and seal material, and the fluid. Buyers in the GCC often have NPT or G threads on site, so say which thread standard the piping uses.
Facts checked against SMC's published corporate history, October 2026.
Browse SMC products by category: Regulators, Solenoid Valve.
FAQ
Questions about the SMC KK4P-02MS S Coupler Plug R1/4 Male Thread
Answers from our engineering team on installation, compatibility and integration.
01What does KK4P-02MS mean?
KK is the S coupler series, 4 the 1/4 size, P the plug, 02 the R1/4 port, M male thread and S sealant.
02Which socket does it fit?
KK4S-02MS and the other size 4 sockets of the KK series.
03What is the effective area?
39 mm2 for the coupled KK4P-02MS and KK4S-02MS pair.
04What pressure range applies?
0 to 1 MPa, with a 1.5 MPa proof pressure.
05What temperature range applies?
-5 to 60 deg C for air.
Reviews
There are no reviews yet.