This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX275, 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 SI50BX275
The AirTAC Airtac SI50 Standard Cylinder SI50BX275 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 275mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX275, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke275 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX275
- 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 SI50BX275
The AirTAC SI50BX275 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 275mm stroke. It delivers 982N push and 825N pull at 0.5MPa. The direct replacement is the SAI50BX275, matching the G1/4 port, M16x1.5 rod thread, and 30mm cushions.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure. This SKU lacks a magnet (-S), so it cannot take CS1-B/DS1-B sensors. The -B rod is SUS304 stainless.
Airtac SI50 Standard Cylinder SI50BX275 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX275 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX275 |
| Bore size | Ø50 mm |
| Stroke | 275 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 SAI50BX275 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 SAI50BX275 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 SI50BX275
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×275 | 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 SI50BX275 Is Used
Package Diversion
Actuates routing gates on packaging lines using the 982N push force at 0.5MPa to deflect medium-weight cartons reliably.
Clamp Actuation
Provides 275mm travel to position and secure workholding fixtures on machining centers, utilizing the SUS304 stainless rod.
Vertical Lift Stops
Controls descent stops for 50kg material trays, requiring external pilot check valves since cushions cannot hold loads.
Replacing the Airtac SI50 Standard Cylinder SI50BX275 with the SAI50BX275
To replace the SI50BX275, order the SAI50BX275. Verify the ISO 15552 mounting interface, G1/4 port, and 275mm stroke. Sizing both ways: a 63mm bore yields 1559N push at 0.5MPa, while a 40mm bore yields 628N. For the 275mm stroke, add external guides to prevent rod bending under side loads. This non-magnet SKU cannot support switches. For load holding on air loss, use an external pilot check valve or the SAIL/BSAI lock variant, as cushions only decelerate.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX275
- ✓ 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 SI50BX275 FAQ
Yes, the SI50BX275 is discontinued. The direct replacement is the SAI50BX275, which shares the same ISO 15552 mounting interface, 50mm bore, 275mm stroke, G1/4 port, and output force.
It operates at 30-800 mm/s with a G1/4 port. Force ratings: push 982N and pull 825N at 0.5MPa, push 1374N at 0.7MPa, push 1767N at 0.9MPa, and a theoretical max of 200 kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX275
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX275 replacement — usually within 7-8 hours.