Fittings, Tubing & Flow Control
Automation Distribution stocks over 12,000 SMC pneumatic fittings, tubing, and flow control SKUs — everything needed to route, connect, and control compressed air between your valves, cylinders, and FRL units. As an authorized SMC Corporation of America distributor, we carry the full KQ2 one-touch fitting series, SMC polyurethane and nylon pneumatic tubing, AS series speed controllers, check valves, quick couplers, and air distribution manifolds, with same-day shipping on in-warehouse stock from Hatfield, PA.
Shop SMC pneumatic fittings, tubing & flow control by type
Pneumatic fittings — KQ2 one-touch and specialty series
SMC's KQ2 series is the most widely stocked push-in one-touch fitting family in North American pneumatics. Tube inserts with a single push and releases with a collet press — no tools, no thread tape, no wrenches. Available in metric and inch tube OD sizes from 3/32" (2.5mm) to 3/8" (9.5mm), with male NPT, BSPT (R), and BSPP (G) thread options, in straight, elbow, tee, Y, union, and cap configurations.
Key KQ2 sub-series: KQ2H (male connector), KQ2L (male elbow), KQ2T (branch tee), KQ2U (branch Y), KQ2V (universal male elbow), KQ2K (45° male elbow), KQ2Y (male run tee), KQ2S (hex head male connector with face seal), KQ2W (union), KQ2C (cap). Specialty fittings include the KFG2 stainless steel 316 insert fitting series for chemical and corrosive environments, the KGL stainless one-touch series, and the KAT antistatic fitting series for semiconductor and ESD-sensitive applications. 6,883 SKUs.
Pneumatic tubing — polyurethane, nylon, and specialty
SMC pneumatic tubing is designed for compatibility with KQ2 and other SMC one-touch fittings, in outside diameter sizes that match KQ2 collet sizing directly. Polyurethane (PU) tubing is the standard choice for most machine pneumatic circuits — flexible, kink-resistant, and available in multiple colors for circuit identification. Nylon tubing provides higher pressure rating and improved abrasion resistance for more demanding routing environments. Soft nylon offers improved flexibility versus standard nylon in tight routing applications.
Available in metric OD sizes (4mm, 6mm, 8mm, 10mm, 12mm) and inch sizes, in straight lengths and coiled configurations. Color options include blue, black, red, green, white, and clear depending on material and size.
Speed controllers — AS series
SMC AS series speed controllers (needle valves with one-touch fitting connections) are the standard method for controlling pneumatic cylinder speed in both the extend and retract directions. Installed in the cylinder port line, the needle valve restricts exhaust airflow to control piston velocity — this is called meter-out control, and it is the correct method for most cylinder speed control applications because it provides stable, consistent speed under load.
Available in inline (AS-F series, push-lock) and elbow (AS series, standard) configurations, in M5, 1/8", 1/4", 3/8", and 1/2" port sizes, with compatible one-touch tube OD sizes from ø3mm to ø16mm. Specialty variants include AS-FG stainless steel (for corrosive environments), AS-FS with flow indicator window (visual confirmation of airflow), and JASV exhaust speed controller (compact push-lock elbow type). Also available in banjo-bolt style for direct cylinder port mounting.
Check valves
SMC pneumatic check valves allow airflow in one direction only, blocking reverse flow. Used in pneumatic circuits to hold pressure, prevent backflow from parallel circuits, and maintain actuator position when supply pressure is lost. Available in inline and elbow configurations with one-touch fitting connections for direct in-line installation without additional hardware.
Quick couplers
SMC quick couplers (also called quick disconnects) allow pneumatic lines to be connected and disconnected without tools and without shutting off system pressure, using a ball-lock sleeve mechanism. Used at machine interfaces, end-of-arm tooling connections, pneumatic gun and tool connections, and anywhere temporary or frequent pneumatic connections are required. Available in NPT and metric thread versions, multiple body sizes, and with or without shut-off valve in the socket half.
Air distribution manifolds
SMC pneumatic manifolds distribute a single compressed air supply source to multiple output ports, simplifying panel plumbing for multi-cylinder or multi-valve circuits. Manifold blocks are available in aluminum and stainless steel with 2 to 20 outlets, in NPT and metric port threads. Note: