This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX155, 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 SI50BX155
The AirTAC Airtac SI50 Standard Cylinder SI50BX155 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 155mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX155, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke155 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX155
- 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 SI50BX155
The AirTAC SI50BX155 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 155mm stroke. It delivers 982N push force at 0.5MPa via a G1/4 port. The direct replacement is the SAI50BX155, matching the interface, force, and port exactly. Note that 155mm is a nonstandard stroke.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure. This SKU uses a SUS304 stainless rod (-B) and lacks a magnet, so it cannot take a sensor.
Airtac SI50 Standard Cylinder SI50BX155 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX155 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX155 |
| Bore size | Ø50 mm |
| Stroke | 155 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 SAI50BX155 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 SAI50BX155 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 SI50BX155
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×155 | 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 SI50BX155 Is Used
Stainless Rod Actuation
Ideal for moderate-wear production lines where the SUS304 rod resists corrosion better than standard carbon steel.
Nonstandard Stroke Diverting
The specific 155mm stroke handles exact diverting or gating tasks on conveyor systems where standard strokes fall short.
Replacing the Airtac SI50 Standard Cylinder SI50BX155 with the SAI50BX155
To replace the SI50BX155, order the SAI50BX155. Confirm the ISO 15552 mounting interface, G1/4 port, and 155mm nonstandard stroke. This SKU has no magnet (-S), so CS1-B/DS1-B sensors cannot be used. For higher force, the 63mm bore offers 1559N at 0.5MPa; for less, the 40mm bore gives 628N. The cushion only decelerates; for load holding on air loss, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants. At 155mm, side-load risk is low, but ensure straight alignment.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX155
- ✓ 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 SI50BX155 FAQ
Yes, the SI50BX155 is discontinued. The direct replacement is the SAI50BX155, a true ISO 15552 profile cylinder that matches the 50mm bore, 155mm stroke, G1/4 port, and mounting interface.
The G1/4 port feeds a 50mm bore that yields 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, and a theoretical max of 200kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX155
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX155 replacement — usually within 7-8 hours.