This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125AX450, 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 SI125AX450
The AirTAC SI125 Standard Cylinder SI125AX450 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 450mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125AX450, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke450 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125AX450
- 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 SI125AX450
The AirTAC SI125AX450 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 450 mm stroke. Delivering 6136 N push and 5734 N pull at 0.5 MPa, it features a G1/2 port, M27x2 rod thread, and 40 mm adjustable air cushions. The direct replacement is the SAI125AX450, matching the interface, force, and port. Because this SKU lacks the -S suffix, it has no magnet and cannot accept a sensor. The A suffix denotes a SUS420J2 stainless steel piston rod for corrosion resistance.
The SAI125AX450 upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. The SAI family also adds SAIL and BSAI lock variants absent in the SI line.
Airtac SI125 Standard Cylinder SI125AX450 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125AX450 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125AX450 |
| Bore size | Ø125 mm |
| Stroke | 450 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 SAI125AX450 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 SAI125AX450 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 SI125AX450
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×450 | 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 SI125AX450 Is Used
Heavy Stamping Press
Drives large platens in metal forming with 6136 N push at 0.5 MPa, relying on the 40 mm cushions to absorb end-of-stroke impact.
Pallet Lift Station
Lifts heavy loads vertically; the SUS420J2 stainless rod resists humidity in damp dispatch zones while moving goods 450 mm.
Mold Clamping Fixture
Secures large injection molds using the ISO 15552 mounting interface, providing rigid 125 mm bore actuation.
Replacing the Airtac SI125 Standard Cylinder SI125AX450 with the SAI125AX450
To replace the SI125AX450, order the SAI125AX450. It drops into existing fixtures via the ISO 15552 mounting interface, matching the 125 mm bore, 450 mm stroke, G1/2 port, and mounting accessories. Confirm your thread choice (PT, G, or NPT). Since this is a no-S SKU, it cannot take a CS1-B/DS1-B sensor; if sensing is needed, switch to an SAI125X450S. The A suffix specifies the SUS420J2 stainless rod; default is carbon steel. For sizing, neighbouring bores are 100 mm (3927 N push @0.5) and 160 mm (10053 N push @0.5). Note that a plain cylinder drifts on air loss; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. With a 450 mm stroke, use external guides to prevent rod bending and side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125AX450
- ✓ 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 SI125AX450 FAQ
Yes, the SI125AX450 is discontinued. The direct replacement is the SAI125AX450, which shares the same ISO 15552 mounting interface, 125 mm bore, 450 mm stroke, G1/2 port, and force ratings.
At 0.5 MPa it pushes 6136 N and pulls 5734 N. Push is 8590 N at 0.7 MPa and 11045 N at 0.9 MPa. The theoretical max is 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s. It uses a G1/2 port.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125AX450
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125AX450 replacement — usually within 7-8 hours.