This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX20S, 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 SI50BX20S
The AirTAC Airtac SI50 Standard Cylinder SI50BX20S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 20mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX20S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke20 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX20S
- 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 SI50BX20S
The AirTAC SI50BX20S is a discontinued double-acting ISO 15552 profile cylinder featuring a SUS304 stainless piston rod and a 20 mm stroke. It delivers 982 N push force at 0.5 MPa through a G1/4 port. The direct replacement is the SAI50BX20S, matching the bore, stroke, force, and ISO 15552 mounting interface exactly.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. The SAI family also adds SAIL, SAIF, and BSAI lock variants absent from the SI line.
Airtac SI50 Standard Cylinder SI50BX20S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX20S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX20S |
| Bore size | Ø50 mm |
| Stroke | 20 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 SAI50BX20S 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 SAI50BX20S 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 SI50BX20S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×20 | 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 SI50BX20S Is Used
Short-Stroke Clamping
Ideal for compact clamping fixtures requiring precise 20 mm actuation with a corrosion-resistant SUS304 rod.
Diverting Mechanism
Provides reliable 982 N push force to divert light packages on a manufacturing line at 0.5 MPa.
Part Ejection
Ejects machined components quickly with adjustable end cushions protecting the assembly from impact.
Replacing the Airtac SI50 Standard Cylinder SI50BX20S with the SAI50BX20S
To replace the SI50BX20S, order the SAI50BX20S keeping the S magnet for current AirTAC switches and the B SUS304 rod. Verify the G1/4 port, M16x1.5 thread, and ISO 15552 mounting. For sizing, the 50 mm bore yields 982 N push at 0.5 MPa; step down to a 40 mm bore for 628 N or up to a 63 mm bore for 1559 N. This cylinder does not hold load without live air; use a pilot check valve or SAIL lock variant. The 20 mm stroke runs safely without side-load guides.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX20S
- ✓ 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 SI50BX20S FAQ
Yes, the SI50BX20S is discontinued. The direct replacement is the SAI50BX20S. It shares the identical ISO 15552 mounting interface, 50 mm bore, 20 mm stroke, G1/4 port, and output force, fitting existing fixtures perfectly.
The 50 mm bore cylinder uses a G1/4 port. It delivers 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and a theoretical maximum force of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX20S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX20S replacement — usually within 7-8 hours.