This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI40X50H, 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 SI40X50H
The AirTAC Airtac SI40 Standard Cylinder SI40X50H 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 SAI40X50H, 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 → SAI40X50H
- 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 SI40X50H
The AirTAC SI40X50H is a discontinued double-acting ISO 15552 profile cylinder with a 40 mm bore, 50 mm stroke, and a Viton H high-temperature seal (0 to 150 C). Delivering 628 N push force at 0.5 MPa via a G1/4 port, this legacy unit is replaced by the SAI40X50H. The SAI is a direct: identical ISO 15552 mounting interface, bore, stroke, output force, port size, and M12x1.25 rod thread.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Note this SKU lacks a magnet (-S) and cannot accept a sensor; the SI family used CS1-B/DS1-B switches, while SAIL lock and SAIF valve variants expand the current line.
Airtac SI40 Standard Cylinder SI40X50H Technical Specifications
| Model | Airtac SI40 Standard Cylinder SI40X50H |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI40X50H |
| 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 SAI40X50H 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 SAI40X50H 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 SI40X50H
| 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 SI40X50H Is Used
Hot-End Part Ejection
Short-stroke ejection of molded components near heat zones, leveraging the Viton H seal to withstand 150 C ambient temperatures without degrading.
Diverting Arm Actuation
Driving a short 50 mm diverting pop-up arm on a packaging line, providing 628 N of push force to reliably shift products between parallel belts.
Clamp Release Mechanism
Actuating a low-profile clamping fixture where 377 N of safe working force securely holds light workpieces during secondary machining operations.
Replacing the Airtac SI40 Standard Cylinder SI40X50H with the SAI40X50H
To replace the SI40X50H, order the SAI40X50H. Verify your ISO 15552 mounting accessory (LB, FA, TC, etc.), the G1/4 air port, and the M12x1.25 rod thread. Because this specific SKU has no magnet, it cannot hold a sensor; if position detection is needed, select an SAI40X50HS. The 50 mm stroke is short, so side-load risks are minimal, but always guide the load. At 0.5 MPa, a 40 mm bore yields 628 N push and 528 N pull; if you need less force, a 32 mm bore provides 402 N, and if you need more, a 50 mm bore offers 982 N. Remember, a plain cylinder drifts on air loss—the cushion only decelerates. For load holding, use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI40X50H
- ✓ 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 SI40X50H FAQ
Yes, the SI40X50H is discontinued. The direct replacement is the SAI40X50H. It shares the exact same ISO 15552 mounting interface, 40 mm bore, 50 mm stroke, G1/4 port, and Viton H high-temperature seal, fitting directly into existing fixtures.
The 40 mm bore features a G1/4 air port and M12x1.25 rod thread. Force output is 628 N push and 528 N pull at 0.5 MPa, 879 N push at 0.7 MPa, 1130 N push at 0.9 MPa, with a theoretical maximum of 128 kgf at 1.0 MPa. Operating speed is 30-800 mm/s.
Request a Quote for the SAI40X50H
Send us the quantity and destination. We confirm price, stock and lead time on the SAI40X50H replacement — usually within 7-8 hours.