This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X50S, with the same bore, stroke, output force, port and mounting, so it fits the same application. The SAI replacement keeps the same ISO 15552 mounting interface, bore, stroke, output force and accessories, so it drops straight into existing fixtures. It is the current-production version of this cylinder with an upgraded piston seal.
Airtac SI40 Standard Cylinder SI40X50S
The AirTAC SI40 Standard Cylinder SI40X50S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø40mm bore and 50mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI40X50S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ40 mm
- Stroke50 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM12×1.25
- StatusDiscontinued → SAI40X50S
- No minimum order. A single piece can be ordered.
- Ready in 3–5 business days. That is the time we take to process the order and hand it to the carrier. Transit time after that depends on the destination.
About the Airtac SI40 Standard Cylinder SI40X50S
The AirTAC SI40X50S is a discontinued double-acting ISO 15552 profile cylinder with a 40mm bore and 50mm stroke. It delivers 628N push force at 0.5MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI40X50S, a direct replacement retaining the exact mounting interface, bore, and output force.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. The SAI family also adds SAIL, SAIF, and BSAI lock variants the SI lacked.
Airtac SI40 Standard Cylinder SI40X50S Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X50S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X50S |
| Bore size | Ø40 mm |
| Stroke | 50 mm |
| Acting type | Double acting |
| Port size | G1/4 |
| Rod thread | M12×1.25 |
| Fluid | Air (filtered by 40µm element) |
|---|---|
| Operating pressure | 0.15 – 1.0 MPa |
| Proof pressure | 1.5 MPa |
| Temperature | -20 to +70 °C |
| Speed range | 30 – 800 mm/s |
| Cushion | Adjustable, 27 mm |
| Max standard stroke | Up to 1200 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI40X50S carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø40mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 628 N | 528 N |
| 0.7 MPa | 880 N | — |
| Max (@1.0 MPa) | 128 kgf | |
The SAI40X50S produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI40 Standard Cylinder SI40X50S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 40 | Bore size in mm. |
| ×50 | Stroke length in mm. |
| -S | Optional built-in magnet for sensor position sensing. |
Legacy SI-family variants: SID (double rod), SIJ (adjustable stroke) — each maps to its SAI equivalent (SID→SAID, SIJ→SAIJ). Rod material: carbon steel (blank) / SUS420J2 (A) / SUS304 (B).
Where the Airtac SI40 Standard Cylinder SI40X50S Is Used
Small Part Clamping
Ideal for holding light machined components during drilling or milling, utilizing the 628N push force at 0.5MPa for secure, stable fixturing.
Package Diverting
Provides rapid 50mm stroke actuation to push small cartons off a handling line, operating efficiently at speeds between 30-800mm/s.
Stopper Gate Control
Acts as a compact pneumatic stopper for tote boxes on roller conveyors, with the -S magnet enabling position confirmation via CS1-B switches.
Replacing the Airtac SI40 Standard Cylinder SI40X50S with the SAI40X50S
To replace the SI40X50S, order the SAI40X50S. Confirm the ISO 15552 interface, 50mm stroke, G1/4 port (PT/G/NPT), M12x1.25 rod thread, and the -S magnet for CS1-B/DS1-B legacy sensors. If you need more force, the neighbouring 50mm bore provides 982N push at 0.5MPa; if less is required, the 32mm bore offers 402N. Note that a plain cylinder drifts on air loss—the cushion only decelerates. For held loads, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X50S
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI40 Standard Cylinder SI40X50S FAQ
Yes, the SI40X50S is discontinued. The direct replacement is the SAI40X50S. It matches the ISO 15552 mounting interface, 40mm bore, 50mm stroke, G1/4 port, and output force, fitting directly into existing fixtures.
The G1/4 port bore delivers a push force of 628N and pull of 528N at 0.5MPa. At 0.7MPa push is 879N, and 1130N at 0.9MPa. The theoretical maximum force is 128kgf at 1.0MPa.
Request a Quote for the SAI40X50S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X50S replacement — usually within 7-8 hours.