This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX140S, 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 SI50BX140S
The AirTAC Airtac SI50 Standard Cylinder SI50BX140S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 140mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX140S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke140 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX140S
- 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 SI50BX140S
The AirTAC SI50BX140S is a discontinued double-acting ISO 15552 profile cylinder featuring a 50mm bore, 140mm stroke, and a SUS304 stainless steel rod. It delivers 982 N of push force and 825 N of pull force at 0.5 MPa, operating through a G1/4 port. AirTAC replaced this legacy unit with the SAI50BX140S, a direct replacement retaining the exact ISO 15552 mounting interface, bore, stroke, output force, and port size.
The SAI upgrade introduces an improved piston seal with two Y-shaped one-way elements for lower start-up pressure and longer life. This -S variant includes a piston magnet for legacy CS1-B/DS1-B sensors, and the SAI family now offers SAIL and BSAI lock variants the original SI lacked.
Airtac SI50 Standard Cylinder SI50BX140S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX140S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX140S |
| Bore size | Ø50 mm |
| Stroke | 140 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 SAI50BX140S 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 SAI50BX140S 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 SI50BX140S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×140 | 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 SI50BX140S Is Used
Stainless Rod Diverters
Ideal for diverting packages on a washdown conveyor line, leveraging the SUS304 rod for corrosion resistance while providing 982 N of push force at 0.5 MPa.
Pneumatic Clamping Jigs
Deploys 140mm of travel to actuate clamping arms inside machining jigs, using the built-in magnet for end-of-stroke position confirmation.
Replacing the Airtac SI50 Standard Cylinder SI50BX140S with the SAI50BX140S
To replace the discontinued SI50BX140S, order the SAI50BX140S. Confirm the ISO 15552 mounting interface, the 50mm bore, 140mm stroke, G1/4 port (PT/G/NPT thread options), and your specific mounting accessory. This unit has the -B SUS304 stainless rod and -S magnet for CS1-B/DS1-B switches. If sizing up or down, neighbouring bores are 40mm (628 N push @0.5 MPa) and 63mm (1559 N push @0.5 MPa). A plain cylinder drifts on air loss since the cushion only decelerates; for load holding, use an external pilot check valve or the SAIL/BSAI lock variant. At 140mm stroke, side-load and rod-bending stresses are low, but always guide the load.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX140S
- ✓ 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 SI50BX140S FAQ
Yes, the SI50BX140S is discontinued. The direct replacement is the SAI50BX140S. It shares the identical ISO 15552 mounting interface, 50mm bore, 140mm stroke, G1/4 port, and output force, fitting directly into existing fixtures.
This 50mm bore cylinder uses a G1/4 air port. The thrust figures are: 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 theoretical maximum force of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX140S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX140S replacement — usually within 7-8 hours.