This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX250, 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 SI50AX250
The AirTAC Airtac SI50 Standard Cylinder SI50AX250 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 SAI50AX250, 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 → SAI50AX250
- 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 SI50AX250
The AirTAC SI50AX250 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 250mm stroke. It delivers 982 N push and 825 N pull at 0.5 MPa through a G1/4 port. AirTAC replaced this legacy unit with the SAI50AX250, a direct upgrade retaining the exact ISO 15552 mounting interface, bore, stroke, force, port and accessories.
The SAI upgrade features a refined piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. The SAI family also introduces SAIL, SAIF and BSAI lock variants absent from the SI line. This specific SKU lacks a magnet, meaning it cannot accept position switches.
Airtac SI50 Standard Cylinder SI50AX250 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX250 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX250 |
| 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 SAI50AX250 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 SAI50AX250 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 SI50AX250
| 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 SI50AX250 Is Used
Package Diversion
Routes medium-weight cartons on packaging lines using the 982 N push force at 0.5 MPa without overstressing the mechanism.
Material Ejection
Pushes completed parts out of assembly zones, utilizing the 30 mm adjustable air cushions at both ends to decelerate the 250mm stroke smoothly.
Replacing the Airtac SI50 Standard Cylinder SI50AX250 with the SAI50AX250
To replace the SI50AX250, order the SAI50AX250. Verify the ISO 15552 mounting interface, 50mm bore, 250mm stroke, G1/4 port (PT/G/NPT) and mounting accessory. Because this SKU lacks a magnet (-S), it cannot support sensors; if sensing is needed, order an SAI50X250S. For sizing both ways, a 40mm bore yields 628 N push at 0.5 MPa, while a 63mm bore yields 1559 N. At 250mm stroke, ensure adequate guide support to prevent rod bending and side loads. A plain cylinder drifts on air loss; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX250
- ✓ 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 SI50AX250 FAQ
Yes, the AirTAC SI50AX250 is discontinued. The direct replacement is the SAI50AX250. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 250mm stroke, 982 N force, G1/4 port and mounting interface.
This double-acting cylinder has a G1/4 air port and M16x1.5 rod thread. It generates 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, 1767 N push at 0.9 MPa, and a theoretical max of 200 kgf at 1.0 MPa. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX250
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX250 replacement — usually within 7-8 hours.