This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX25SH, 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 SI50BX25SH
The AirTAC SI50 Standard Cylinder SI50BX25SH is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 25mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX25SH, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke25 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX25SH
- 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 SI50BX25SH
The AirTAC SI50BX25SH is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 25mm stroke, and Viton H high-temperature seals (0 to 150 C). It features a SUS304 stainless piston rod (-B) and a built-in magnet (-S) for CS1-B/DS1-B switches. Delivering 982 N push at 0.5 MPa, the direct replacement is the SAI50BX25SH, which preserves the exact G1/4 port, M16x1.5 thread, and ISO 15552 mounting interface.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and extended life. Note that a standard cylinder drifts on air loss; the cushion only decelerates. For secure holding, use an external pilot check valve or the SAIL/BSAI lock variants.
Airtac SI50 Standard Cylinder SI50BX25SH Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX25SH |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX25SH |
| Bore size | Ø50 mm |
| Stroke | 25 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 SAI50BX25SH 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 SAI50BX25SH 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 SI50BX25SH
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×25 | 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 SI50BX25SH Is Used
High-Temp Clamping
Short-stroke clamping of machined parts in heated environments, utilising the Viton H seals and SUS304 rod for thermal and corrosion resistance.
Diverting Gate
Actuating routing flaps on conveyor lines where the 982 N force at 0.5 MPa easily overcomes friction and package weight.
Replacing the Airtac SI50 Standard Cylinder SI50BX25SH with the SAI50BX25SH
To replace the discontinued SI50BX25SH, order the SAI50BX25SH direct equivalent, verifying the ISO 15552 mounting interface, 50mm bore, 25mm stroke, G1/4 port, and Viton H seal. The -B rod (SUS304) and -S magnet (for CS1-B/DS1-B switches) must be specified. If downsizing, a 40mm bore yields 628 N push at 0.5 MPa; if uprating, a 63mm bore provides 1559 N. Remember that standard cylinders do not hold load without live air—select the SAIL lock or BSAI clamp-lock variant if drift prevention is required. For this 25mm stroke, side-load risks are minimal, but always guide the load to prevent rod bending.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX25SH
- ✓ 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 SI50BX25SH FAQ
Yes, the SI50BX25SH is discontinued. The direct replacement is the SAI50BX25SH. It is dimensionally interchangeable per ISO 15552, maintaining the same 50mm bore, 25mm stroke, 982 N force, G1/4 port, and mounting fixtures.
The 50mm bore features a G1/4 air port. Force output is 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. It operates at speeds of 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX25SH
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX25SH replacement — usually within 7-8 hours.