This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX375S, 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 SI50BX375S
The AirTAC Airtac SI50 Standard Cylinder SI50BX375S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 375mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX375S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke375 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX375S
- 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 SI50BX375S
The AirTAC SI50BX375S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 375mm stroke, G1/4 port, and an SUS304 stainless piston rod (-B). It delivers 982 N push and 825 N pull at 0.5 MPa. AirTAC replaced this end-of-line unit with the SAI50BX375S direct replacement, matching the exact ISO 15552 mounting interface, stroke, force, and porting for existing fixtures.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. The -S magnet pairs with legacy CS1-B/DS1-B switches, while the SAI family adds SAIL, SAIF, and BSAI lock variants the SI lacked.
Airtac SI50 Standard Cylinder SI50BX375S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX375S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX375S |
| Bore size | Ø50 mm |
| Stroke | 375 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 SAI50BX375S 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 SAI50BX375S 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 SI50BX375S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×375 | 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 SI50BX375S Is Used
Diverting Gate Actuation
Drives routing flaps on packaging lines using the 982 N push force, while the SUS304 rod withstands washdown environments.
Pallet Stopper Assembly
Acts as a pneumatic stop in conveyor endpoints, decelerating smoothly via the 30mm adjustable air cushions at both ends.
Replacing the Airtac SI50 Standard Cylinder SI50BX375S with the SAI50BX375S
To replace the SI50BX375S, order the SAI50BX375S and confirm the ISO 15552 mounting interface, G1/4 port, M16x1.5 rod thread, and -S magnet for current AirTAC switches. The -B SUS304 rod provides corrosion resistance over standard carbon steel. If you need more force, the 63mm bore yields 1559 N push at 0.5 MPa; if less, the 40mm bore yields 628 N. Note that a plain cylinder drifts on air loss—the cushion only decelerates—so use an external rod lock or pilot check valve for load holding, or specify the SAIL/BSAI lock variant. Because the 375mm stroke increases side-load and rod-bending risks, use an external guide to prevent premature wear.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX375S
- ✓ 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 SI50BX375S FAQ
Yes, the SI50BX375S is discontinued. The direct replacement is the SAI50BX375S. It is dimensionally interchangeable per ISO 15552, maintaining the same 50mm bore, 375mm stroke, G1/4 port, and mounting interface to fit existing fixtures directly.
The G1/4 port bore delivers a push of 982 N and pull of 825 N at 0.5 MPa. At 0.7 MPa push is 1374 N, and 1767 N at 0.9 MPa. The theoretical maximum force is 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX375S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX375S replacement — usually within 7-8 hours.