This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX90S, 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 SI50BX90S
The AirTAC Airtac SI50 Standard Cylinder SI50BX90S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 90mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX90S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke90 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX90S
- 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 SI50BX90S
The AirTAC SI50BX90S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 90mm stroke, and a SUS304 stainless steel rod. Delivering 982 N push force at 0.5 MPa, it features a built-in piston magnet for CS1-B/DS1-B sensors and a G1/4 port. AirTAC replaced this legacy unit with the SAI50BX90S, a direct replacement sharing the exact ISO 15552 mounting interface, force, and stroke.
The SAI upgrade utilizes an advanced two Y-shaped one-way piston seal for lower start-up pressure and extended life. Note that plain cylinders drift without live air; for load holding, explore the SAIL or BSAI lock variants.
Airtac SI50 Standard Cylinder SI50BX90S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX90S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX90S |
| Bore size | Ø50 mm |
| Stroke | 90 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 SAI50BX90S 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 SAI50BX90S 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 SI50BX90S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×90 | 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 SI50BX90S Is Used
Stainless Rod Actuation
Ideal for packaging machinery where the SUS304 rod resists washdown corrosion while providing 982 N of push force at 0.5 MPa.
Mid-Stroke Diverting
The 90mm stroke offers precise movement for diverter gates on material handling lines without occupying excessive space.
Vertical Lift Gates
With a safe vertical lift capacity around 50 kg, this cylinder easily raises and lowers lightweight access doors and safety barriers.
Replacing the Airtac SI50 Standard Cylinder SI50BX90S with the SAI50BX90S
To replace the discontinued SI50BX90S, order the SAI50BX90S. Verify your existing fixture matches the ISO 15552 mounting dimensions, 50mm bore, 90mm stroke, G1/4 port, and M16x1.5 rod thread. Because this SKU includes the -S magnet and -B SUS304 rod, confirm these attributes carry over. When sizing, a 40mm bore yields 628 N push at 0.5 MPa, while a 63mm bore provides 1559 N. The standard 30-800 mm/s speed range suits most tasks. Remember, the air cushion only decelerates; it does not hold position. If you need static holding on air loss, use an external pilot check valve or select the SAIL air-released lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX90S
- ✓ 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 SI50BX90S FAQ
Yes, the AirTAC SI50BX90S is discontinued. The direct replacement is the SAI50BX90S. It shares the identical ISO 15552 mounting interface, 50mm bore, 90mm stroke, G1/4 port, and output force, fitting directly into existing fixtures.
This double-acting cylinder uses a G1/4 air port. It generates 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and a theoretical maximum of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX90S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX90S replacement — usually within 7-8 hours.