This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX145S, 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 SI50BX145S
The AirTAC Airtac SI50 Standard Cylinder SI50BX145S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 145mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX145S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke145 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX145S
- 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 SI50BX145S
The AirTAC SI50BX145S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 145mm stroke, and a SUS304 stainless piston rod. Generating 982N push force at 0.5MPa, it is replaced by the SAI50BX145S. This direct upgrade matches the G1/4 port, M16x1.5 thread, and 30mm cushions, while adding a two Y-shaped one-way piston seal for low start-up pressure.
The SAI family introduces SAIL, SAIF, and BSAI lock variants absent in the SI line. This -S model uses legacy CS1-B/DS1-B sensors, whereas the SAI takes current AirTAC switches. Note that 145mm is a nonstandard stroke, and plain cylinders drift without air; use SAIL or an external rod lock for load holding.
Airtac SI50 Standard Cylinder SI50BX145S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX145S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX145S |
| Bore size | Ø50 mm |
| Stroke | 145 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 SAI50BX145S 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 SAI50BX145S 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 SI50BX145S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×145 | 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 SI50BX145S Is Used
Component Seating
Fits parts into fixtures using the 145mm nonstandard stroke, relying on the 30mm adjustable cushions to decelerate at stroke end.
Replacing the Airtac SI50 Standard Cylinder SI50BX145S with the SAI50BX145S
To replace the SI50BX145S, order the SAI50BX145S, confirming the ISO 15552 interface, 50mm bore, 145mm nonstandard stroke, G1/4 port, and magnet. If sizing up, the 63mm bore yields 1559N push at 0.5MPa; sizing down, the 40mm bore gives 628N. For 145mm strokes, guide rods prevent side-load rod bending. The -B SUS304 rod resists corrosion, and a Viton H seal handles 0-150C. Remember, cushions only decelerate; for load holding on air loss, choose the SAIL lock, BSAI clamp-lock, or a pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX145S
- ✓ 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 SI50BX145S FAQ
Yes, the SI50BX145S is discontinued. The direct replacement is the SAI50BX145S. It is dimensionally interchangeable per ISO 15552, matching the 50mm bore, 145mm stroke, G1/4 port, and mounting interface, but upgrades the seal with two Y-shaped elements.
This double-acting cylinder has a G1/4 air port. It delivers 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a theoretical max of 200kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX145S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX145S replacement — usually within 7-8 hours.