This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX900, 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 SI50BX900
The AirTAC Airtac SI50 Standard Cylinder SI50BX900 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 900mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX900, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke900 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX900
- 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 SI50BX900
The AirTAC SI50BX900 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 900mm stroke. It delivers a thrust of 982 N at 0.5 MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI50BX900, a direct upgrade retaining the exact interface, bore, stroke, output force, and mounting hardware.
The SAI successor features an upgraded piston seal using two Y-shaped one-way elements for low start-up pressure and extended life. The SAI family also introduces lock and valve variants like SAIL and BSAI absent in the SI line. Note this specific SKU lacks a magnet and cannot accept position sensors.
Airtac SI50 Standard Cylinder SI50BX900 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX900 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX900 |
| Bore size | Ø50 mm |
| Stroke | 900 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 SAI50BX900 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 SAI50BX900 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 SI50BX900
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×900 | 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 SI50BX900 Is Used
Long-Stroke Material Push
Pushes workpieces along a wide conveyor section over 900mm, utilizing the 982 N thrust at 0.5 MPa to move medium-weight goods reliably between machining stations.
Pallet Denester
Separates empty pallets in a packaging line. The 900mm extension reaches deep into magazines, while the G1/4 port ensures rapid actuation at 30-800 mm/s.
Vertical Lowering Arm
Lowers components into testing fixtures.
Replacing the Airtac SI50 Standard Cylinder SI50BX900 with the SAI50BX900
To replace the SI50BX900, order the SAI50BX900. Verify your ISO 15552 mounting interface (LB, FA, TC, etc.), the G1/4 air port, and the M16x1.5 rod thread. Because this SKU lacks a magnet, it cannot support legacy CS1-B/DS1-B sensors; order a magnet-equipped SAI50X900S if position detection is required. For sizing, the 50mm bore yields 982 N push at 0.5 MPa; stepping down to a 40mm bore drops force to 628 N, while a 63mm bore increases it to 1559 N. With a 900mm stroke, prevent rod bending by guiding the load externally to avoid side-load damage. A plain cylinder drifts on air loss; for load holding, use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX900
- ✓ 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 SI50BX900 FAQ
Yes, the SI50BX900 is discontinued. The direct replacement is the SAI50BX900. It is dimensionally interchangeable per ISO 15552, matching the 50mm bore, 900mm stroke, G1/4 port, and mounting interface, so it fits existing fixtures directly.
The G1/4 port supplies a push force of 982 N and a pull force of 825 N at 0.5 MPa. At 0.7 MPa the push force is 1374 N, and the theoretical maximum is 200 kgf at 1.0 MPa. The piston rod is 20mm with an M16x1.5 thread.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX900
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX900 replacement — usually within 7-8 hours.