This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX70S, 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 SI50BX70S
The AirTAC Airtac SI50 Standard Cylinder SI50BX70S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 70mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX70S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke70 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX70S
- 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 SI50BX70S
The AirTAC SI50BX70S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 70mm stroke, and a SUS304 stainless piston rod. Delivering 982 N push force at 0.5 MPa, it is replaced by the SAI50BX70S. This direct successor shares the exact ISO 15552 mounting interface, G1/4 port, and 200 kgf maximum force.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure. The original -S magnet supports CS1-B/DS1-B sensors, while the SAI family adds SAIL, SAIF, and BSAI lock variants.
Airtac SI50 Standard Cylinder SI50BX70S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX70S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX70S |
| Bore size | Ø50 mm |
| Stroke | 70 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 SAI50BX70S 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 SAI50BX70S 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 SI50BX70S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×70 | 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 SI50BX70S Is Used
Stainless Rod Clamping
Leverages the SUS304 rod and 982 N force to secure raw material in humid washdown environments without surface corrosion.
Package Diverting
Uses the 70mm stroke to push parcels on packaging lines, operating efficiently at 30-800 mm/s with G1/4 pneumatic ports.
Replacing the Airtac SI50 Standard Cylinder SI50BX70S with the SAI50BX70S
To replace the SI50BX70S, order the SAI50BX70S. It drops into existing fixtures via the identical ISO 15552 mounting interface, matching the 50mm bore, 70mm stroke, G1/4 port, M16x1.5 rod thread, and -S magnet. If downsizing, a 40mm bore yields 628 N push at 0.5 MPa; if upsizing, an 63mm bore provides 1559 N. Remember, a standard cylinder drifts without live air—the cushion only decelerates. For load holding, use an external pilot check valve or the SAIL/BSAI lock variant. The -B rod provides SUS304 corrosion resistance, and a Viton H seal raises heat tolerance to 150 C.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX70S
- ✓ 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 SI50BX70S FAQ
Yes, the SI50BX70S is discontinued. The direct replacement is the SAI50BX70S. It is dimensionally interchangeable per ISO 15552, maintaining the same 50mm bore, 70mm stroke, G1/4 port, and mounting fixtures.
The G1/4 port feeds a 50mm bore that generates 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, 1767 N push at 0.9 MPa, and a maximum theoretical force of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX70S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX70S replacement — usually within 7-8 hours.