This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X400SH, 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 SI125X400SH
The AirTAC SI125 Standard Cylinder SI125X400SH is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 400mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X400SH, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke400 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X400SH
- 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 SI125X400SH
The AirTAC SI125X400SH is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 400 mm stroke. It delivers 6136 N push force at 0.5 MPa and features a G1/2 port, M27x2 rod thread, and 40 mm adjustable air cushions. The direct replacement is the SAI125X400SH, matching the bore, stroke, force, port, and ISO 15552 mounting interface exactly. This -H variant uses Viton FKM seals for 0-150 C high-temperature environments.
The SAI upgrade introduces a two-piece Y-shaped piston seal for lower start-up pressure and longer life. The SAI family also adds lock and valve variants (SAIL, BSAI, SAIF) absent in the SI line. Your -S magnet works with legacy CS1-B/DS1-B sensors, though the SAI replacement uses current AirTAC switches.
Airtac SI125 Standard Cylinder SI125X400SH Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X400SH |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X400SH |
| Bore size | Ø125 mm |
| Stroke | 400 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 SAI125X400SH 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 SAI125X400SH 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 SI125X400SH
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×400 | 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 SI125X400SH Is Used
Heavy Stamp Press
Drives large platens in metal forming, using the 6136 N thrust at 0.5 MPa to actuate heavy tooling.
High-Temp Ejection
Ejects molded parts near hot machinery, relying on the Viton H seals to withstand 0 to 150 C environments.
Replacing the Airtac SI125 Standard Cylinder SI125X400SH with the SAI125X400SH
To replace the discontinued SI125X400SH, order the SAI125X400SH direct: it matches the ISO 15552 mounting interface, 125 mm bore, 400 mm stroke, G1/2 port, and Viton H high-temp seal. Keep your existing mounting hardware and CS1-B/DS1-B sensors. When sizing, neighboring bores offer different forces: the 100 mm bore pushes 3927 N at 0.5 MPa, while the 160 mm bore pushes 10053 N. Note that a plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. Because the 400 mm stroke invites rod bending, use external guides to prevent side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X400SH
- ✓ 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 SI125X400SH FAQ
Yes, the SI125X400SH is discontinued. The direct replacement is the SAI125X400SH. It is dimensionally interchangeable per ISO 15552, preserving the 125 mm bore, 400 mm stroke, G1/2 port, and mounting interface.
The 125 mm bore features a G1/2 port. It delivers 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, 11045 N push at 0.9 MPa, and a theoretical max of 1251 kgf at 1.0 MPa. Speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X400SH
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X400SH replacement — usually within 7-8 hours.