This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX250, 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 SI50BX250
The AirTAC Airtac SI50 Standard Cylinder SI50BX250 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 250mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX250, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke250 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX250
- 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 SI50BX250
The AirTAC SI50BX250 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 250mm stroke. It delivers 982N push force at 0.5MPa via a G1/4 port. The direct replacement is the SAI50BX250, matching the exact interface, force and mounting.
This SKU lacks a magnet and cannot accept a sensor. The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure. For load holding, note the air cushion only decelerates; use an external rod lock or pilot check valve.
Airtac SI50 Standard Cylinder SI50BX250 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX250 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX250 |
| Bore size | Ø50 mm |
| Stroke | 250 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 SAI50BX250 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 SAI50BX250 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 SI50BX250
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×250 | 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 SI50BX250 Is Used
Package Diversion
Actuates routing gates on packaging lines where the 982N push force at 0.5MPa easily deflects standard cartons.
Clamp Actuation
Secures medium workpieces during machining, utilizing the 825N pull force for reliable hold-back tension.
Replacing the Airtac SI50 Standard Cylinder SI50BX250 with the SAI50BX250
To replace the SI50BX250, order the SAI50BX250 to retain the ISO 15552 mounting interface, 50mm bore, 250mm stroke and G1/4 port. Because this specific SKU has no magnet, it cannot support legacy CS1-B/DS1-B sensors; order a magnet-equipped SAI if position sensing is required. For sizing, the neighbouring 63mm bore yields 1559N push at 0.5MPa, while dropping to 40mm provides 628N. With a 250mm stroke, ensure guide support to prevent rod bending under side loads. The cushion only decelerates; for dead-load holding, explore the SAIL or BSAI lock variants, or an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX250
- ✓ 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 SI50BX250 FAQ
Yes, the SI50BX250 is discontinued. The direct replacement is the AirTAC SAI50BX250. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 250mm stroke, G1/4 port and mounting fixtures.
The 50mm bore features a G1/4 air port and M16x1.5 rod thread. It provides 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a maximum theoretical force of 200kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX250
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX250 replacement — usually within 7-8 hours.