This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X1040STC, 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 SI50 Standard Cylinder SI50X1040STC
The AirTAC Airtac SI50 Standard Cylinder SI50X1040STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 1040mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X1040STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke1040 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X1040STC
- 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 SI50 Standard Cylinder SI50X1040STC
The AirTAC SI50X1040STC is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 1040mm stroke. It delivers 982N push force at 0.5MPa via a G1/4 port. The direct replacement is the SAI50X1040STC, matching the exact bore, stroke, force, port, and TC trunnion mount.
This SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. The original SI magnet works with CS1-B/DS1-B sensors, while the SAI uses current AirTAC switches. The SAI family also adds SAIL, SAIF, and BSAI lock variants the SI lacked.
Airtac SI50 Standard Cylinder SI50X1040STC Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X1040STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X1040STC |
| Bore size | Ø50 mm |
| Stroke | 1040 mm |
| Acting type | Double acting |
| Port size | G1/4 |
| Rod thread | M16×1.5 |
| 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, 30 mm |
| Max standard stroke | Up to 1200 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI50X1040STC carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø50mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 982 N | 825 N |
| 0.7 MPa | 1374 N | — |
| Max (@1.0 MPa) | 200 kgf | |
The SAI50X1040STC produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI50 Standard Cylinder SI50X1040STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×1040 | 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 SI50 Standard Cylinder SI50X1040STC Is Used
Long-Stroke Material Transfer
Pushes heavy workpieces between machining stations over a 1040mm distance, utilizing the 982N thrust at 0.5MPa with external guide rails to prevent rod bending.
Pallet Push-Off Assembly
Actuates a 50kg load off an accumulation line using the TC trunnion mount to accommodate the slight pivot arc required over the extended length.
Elevated Platform Lowering
Lowers lightweight materials in a vertical descent application, relying on the adjustable 30mm air cushion at both ends to decelerate the payload smoothly.
Replacing the Airtac SI50 Standard Cylinder SI50X1040STC with the SAI50X1040STC
To replace the SI50X1040STC, order the SAI50X1040STC. Confirm the ISO 15552 interface, 50mm bore, 1040mm stroke, G1/4 port (PT/G/NPT thread options), TC trunnion mount, and the -S magnet. Because 1040mm exceeds the 1200mm max standard stroke threshold for this bore, it is a nonstandard stroke requiring careful handling. At 1040mm, the Ø20mm rod is highly susceptible to bending; use external guides to prevent side loads. For sizing, a 40mm bore offers 628N push at 0.5MPa, while a 63mm bore yields 1559N. The cylinder drifts on air loss since the 30mm cushion only decelerates; use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant for load holding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X1040STC
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI50 Standard Cylinder SI50X1040STC FAQ
Yes, the AirTAC SI50X1040STC is discontinued. The direct replacement is the SAI50X1040STC. It is dimensionally interchangeable per ISO 15552, keeping the same 50mm bore, 1040mm stroke, G1/4 port, TC trunnion mount, and 982N force.
The G1/4 port feeds a 50mm bore yielding 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a theoretical max of 200 kgf at 1.0 MPa. It operates at 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X1040STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X1040STC replacement — usually within 7-8 hours.