This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X1650S, 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 SI125 Standard Cylinder SI125X1650S
The AirTAC SI125 Standard Cylinder SI125X1650S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 1650mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X1650S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke1650 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X1650S
- 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 SI125 Standard Cylinder SI125X1650S
The AirTAC SI125X1650S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 1650 mm stroke. It delivers 6136 N push force at 0.5 MPa via a G1/2 port. Because 1650 mm exceeds the 1500 mm standard maximum, this is a non-standard, made-to-order stroke. The direct replacement is the SAI125X1650S, matching the exact bore, stroke, force, port, and ISO 15552 mounting interface.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. The SAI family also adds SAIL, SAIF, and BSAI lock variants the SI lacked. The original -S magnet supports legacy CS1-B/DS1-B sensors, while the SAI uses current AirTAC switches.
Airtac SI125 Standard Cylinder SI125X1650S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X1650S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X1650S |
| Bore size | Ø125 mm |
| Stroke | 1650 mm |
| Acting type | Double acting |
| Port size | G1/2 |
| Rod thread | M27×2.0 |
| 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 – 500 mm/s |
| Cushion | Adjustable, 40 mm |
| Max standard stroke | Up to 1500 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI125X1650S carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø125mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 6136 N | 5734 N |
| 0.7 MPa | 8590 N | — |
| Max (@1.0 MPa) | 1251 kgf | |
The SAI125X1650S produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI125 Standard Cylinder SI125X1650S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×1650 | 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 SI125 Standard Cylinder SI125X1650S Is Used
Long-Stroke Material Transfer
Moves heavy pallets or chassis across 1.65-meter staging zones using 6136 N of thrust at 0.5 MPa.
Large Assembly Press
Actuates heavy-duty jigs over a 1650 mm span, relying on the 40 mm adjustable air cushions for end deceleration.
Replacing the Airtac SI125 Standard Cylinder SI125X1650S with the SAI125X1650S
To replace the SI125X1650S, order the SAI125X1650S. Confirm the ISO 15552 mounting interface, G1/2 port, M27x2 rod thread, and your specific mounting accessory (LB, FA, TC, etc.). The -S magnet means you need current AirTAC switches to replace legacy CS1-B/DS1-B units. Because the 1650 mm stroke exceeds the 1500 mm standard maximum, expect a made-to-order lead time. At 0.5 MPa this bore pushes 6136 N; if you need less force, step down to a 100 mm bore (3927 N), or step up to 160 mm (10053 N) for more. For a 1650 mm stroke, use external guides to prevent rod bending and side-load damage. A plain cylinder drifts on air loss—the cushion only decelerates—so use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant for load holding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X1650S
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI125 Standard Cylinder SI125X1650S FAQ
Yes, the SI125X1650S is discontinued. The direct replacement is the SAI125X1650S. It is dimensionally interchangeable per ISO 15552, matching the 125 mm bore, 1650 mm stroke, 6136 N force, G1/2 port, and mounting fixtures.
The bore is 125 mm with a G1/2 port. At 0.5 MPa it pushes 6136 N and pulls 5734 N. At 0.7 MPa it pushes 8590 N, and 11045 N at 0.9 MPa. The theoretical maximum force is 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X1650S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X1650S replacement — usually within 7-8 hours.