This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X1250SLB, 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 SI50X1250SLB
The AirTAC SI50 Standard Cylinder SI50X1250SLB 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 SAI50X1250SLB, 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 → SAI50X1250SLB
- 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 SI50X1250SLB
The AirTAC SI50X1250SLB is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 1250mm stroke. Because 1250mm exceeds the 1200mm max standard stroke for this bore, it is a non-standard, made-to-order length. It delivers 982 N push and 825 N pull at 0.5 MPa through a G1/4 port. AirTAC replaced the SI line with the SAI family, making SAI50X1250SLB the direct replacement. It retains the same ISO 15552 mounting interface, LB foot bracket, M16x1.5 rod thread, and force ratings.
The SAI upgrade features a new piston seal using two Y-shaped one-way elements for low start-up pressure and long life. The -S magnet supports legacy CS1-B/DS1-B sensors, while the SAI family also adds SAIL, SAIF, and BSAI lock variants the original SI lacked.
Airtac SI50 Standard Cylinder SI50X1250SLB Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X1250SLB |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X1250SLB |
| 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 SAI50X1250SLB 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 SAI50X1250SLB 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 SI50X1250SLB
| 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 SI50X1250SLB Is Used
Long-Stroke Material Transfer
Drives goods across wide work cells using the LB foot mount, utilizing the 982 N push force at 0.5 MPa to shift medium-weight pallets over the 1250 mm travel.
Extended Axis Positioning
Moves tooling carriages along extended linear rails, relying on external guides to prevent rod bending over the 1250 mm non-standard stroke.
Replacing the Airtac SI50 Standard Cylinder SI50X1250SLB with the SAI50X1250SLB
To replace the SI50X1250SLB, order the SAI50X1250SLB. Confirm the ISO 15552 interface, the 50mm bore, the 1250mm non-standard stroke, the G1/4 port, and the LB foot mounting accessory. The -S magnet equips it for CS1-B/DS1-B switches, though the SAI replacement uses current AirTAC sensors. If sizing down, a 40mm bore yields 628 N push at 0.5 MPa; sizing up to 63mm provides 1559 N. A plain cylinder does not hold load without live air, as the cushion only decelerates. For load holding, use an external rod lock, a pilot check valve, or the SAIL/BSAI lock variant. Finally, at 1250mm, prevent rod bending by guiding the load externally to avoid side-load damage.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X1250SLB
- ✓ 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 SI50X1250SLB FAQ
Yes, the SI50X1250SLB is discontinued. The direct replacement is the SAI50X1250SLB. It is dimensionally interchangeable per ISO 15552, matching the 50mm bore, 1250mm stroke, G1/4 port, LB mount, and output force. The SAI simply upgrades the piston seal to two Y-shaped elements for lower start-up pressure.
The 50mm bore features a G1/4 air port. At 0.5 MPa it provides 982 N push and 825 N pull. At 0.7 MPa push is 1374 N, and at 0.9 MPa it is 1767 N. The theoretical maximum force is 200 kgf at 1.0 MPa. Speed ranges from 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X1250SLB
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X1250SLB replacement — usually within 7-8 hours.