This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X1250, 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 SI50X1250
The AirTAC Airtac SI50 Standard Cylinder SI50X1250 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 1250mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X1250, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke1250 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X1250
- 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 SI50X1250
The AirTAC SI50X1250 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 1250mm stroke. Because 1250mm exceeds the 1200mm standard maximum for this bore, it is a non-standard, made-to-order unit. It delivers 982 N push force at 0.5 MPa and uses a G1/4 port. The direct replacement is the SAI50X1250, matching the ISO 15552 mounting interface, stroke, force and porting exactly.
The SAI upgrade features an improved piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Note this specific SKU lacks a magnet (-S), so it cannot accept CS1-B/DS1-B sensors. For load holding on air loss, the cushion only decelerates; you must use an external rod lock or pilot check valve, or switch to the SAIL/BSAI lock variant.
Airtac SI50 Standard Cylinder SI50X1250 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X1250 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X1250 |
| Bore size | Ø50 mm |
| Stroke | 1250 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 SAI50X1250 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 SAI50X1250 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 SI50X1250
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×1250 | 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 SI50X1250 Is Used
Long-Stroke Diversion
Pushes packages across transfer lines using the full 1250mm reach, guided externally to prevent rod bending.
Automated Fixture Actuation
Drives large assembly fixtures where the 50mm bore and ISO 15552 mounting interface provide standardized integration.
Replacing the Airtac SI50 Standard Cylinder SI50X1250 with the SAI50X1250
To replace the discontinued SI50X1250, order the SAI50X1250. Verify your ISO 15552 mounting interface (LB, FA, TC, etc.), the G1/4 air port, and the M16x1.5 rod thread. Because this is a non-standard 1250mm stroke exceeding the 1200mm maximum, expect made-to-order lead times. At 0.5 MPa the 50mm bore gives 982 N push; if you need less force, the 40mm bore offers 628 N, and if you need more, the 63mm bore provides 1559 N. Since the stroke is over 300mm, prevent rod bending by using an external guide to manage side loads. This non-magnetic SKU cannot take a sensor; if position detection is needed, order the SAI50X1250S equivalent. For loads that must not drift on air loss, select the SAIL or BSAI locking variant instead of relying on the cushion.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X1250
- ✓ 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 SI50X1250 FAQ
Yes, the SI50X1250 is discontinued. The direct replacement is the SAI50X1250, which shares the identical ISO 15552 mounting interface, 50mm bore, 1250mm stroke, output force and G1/4 port, fitting directly into existing fixtures.
The bore is 50mm with a G1/4 port. The thrust is 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and a theoretical maximum of 200 kgf at 1.0 MPa. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X1250
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X1250 replacement — usually within 7-8 hours.