This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX125SH, 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 SI50BX125SH
The AirTAC SI50 Standard Cylinder SI50BX125SH is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 125mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX125SH, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke125 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX125SH
- 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 SI50BX125SH
The AirTAC SI50BX125SH is a discontinued double-acting ISO 15552 profile cylinder featuring a 50 mm bore, 125 mm stroke, and a G1/4 air port. Delivering 982 N of push force at 0.5 MPa, it is directly replaced by the SAI50BX125SH. This direct successor shares the exact same ISO 15552 mounting interface, bore, stroke, output force, and port size, fitting existing fixtures perfectly.
The SAI upgrade introduces a refined piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. This specific SI50BX125SH variant includes the -B SUS304 stainless steel piston rod for corrosion resistance and the -H Viton seal, raising the operating temperature range from -20 to +70 C up to 0-150 C.
Airtac SI50 Standard Cylinder SI50BX125SH Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX125SH |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX125SH |
| Bore size | Ø50 mm |
| Stroke | 125 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 SAI50BX125SH 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 SAI50BX125SH 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 SI50BX125SH
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×125 | 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 SI50BX125SH Is Used
Stainless Rod Clamping
Ideal for packaging machinery requiring corrosion resistance, utilizing the SUS304 rod and 982 N force to secure cardboard blanks during hot-melt application.
High-Temp Diversion
The Viton H seal withstands 0-150 C environments, making it suitable for diverting warm molded parts on conveyor lines without seal degradation.
Replacing the Airtac SI50 Standard Cylinder SI50BX125SH with the SAI50BX125SH
To replace the discontinued SI50BX125SH, order the SAI50BX125SH direct equivalent, confirming the ISO 15552 mounting interface, 50 mm bore, 125 mm stroke, G1/4 port, and your specific -B stainless rod, -H high-temp seal, and -S magnet options. The built-in magnet supports legacy CS1-B/DS1-B sensors, while the SAI family utilizes current AirTAC switches. If you need more force, the neighbouring 63 mm bore yields 1559 N at 0.5 MPa; if less is acceptable, the 40 mm bore provides 628 N. Remember that a plain cylinder does not hold load on air loss—the cushion only decelerates. For secure load holding, consider an external rod lock, a pilot-operated check valve, or the SAIL and BSAI lock variants. The 125 mm stroke is under 300 mm, so severe rod-bending side loads are minimal, but proper guide alignment is still recommended.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX125SH
- ✓ 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 SI50BX125SH FAQ
Yes, the AirTAC SI50BX125SH is discontinued. The direct replacement is the SAI50BX125SH. It features the same ISO 15552 mounting interface, 50 mm bore, 125 mm stroke, G1/4 port, and output force, fitting directly into existing setups.
This 50 mm bore cylinder uses a G1/4 air port. It delivers a push force of 982 N and a pull force of 825 N at 0.5 MPa, 1374 N at 0.7 MPa, 1767 N at 0.9 MPa, and a theoretical maximum of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX125SH
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX125SH replacement — usually within 7-8 hours.