This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X400H, 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 SI125X400H
The AirTAC SI125 Standard Cylinder SI125X400H 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 SAI125X400H, 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 → SAI125X400H
- 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 SI125X400H
The AirTAC SI125X400H is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 400mm stroke. It delivers 6136N push and 5734N pull force at 0.5MPa, uses a G1/2 air port, and features a high-temperature Viton H seal for 0-150C environments. The direct replacement is the SAI125X400H, matching the exact bore, stroke, force, port, and ISO 15552 mounting interface.
The SAI successor upgrades the piston seal to two Y-shaped one-way elements for lower start-up pressure and longer life. This SKU lacks a magnet (-S) and cannot accept a sensor. If you need load holding on air loss, the plain cylinder drifts; use the SAIL lock or BSAI clamp-lock variants instead.
Airtac SI125 Standard Cylinder SI125X400H Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X400H |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X400H |
| 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 SAI125X400H 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 SAI125X400H 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 SI125X400H
| 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 SI125X400H Is Used
Heavy Press Clamping
Secures large metal castings in hydraulic press fixtures, utilizing the 6136N push force at 0.5MPa to maintain rigid alignment under high vibration.
Pallet Diversion
Actuates heavy-duty lane diverters for automated pallet routing, where the 400mm stroke and 5734N pull force smoothly shift loaded assemblies.
Mold Ejection
Drives high-temperature mold ejection plates in rubber vulcanization lines, relying on the Viton H seals to withstand 0-150C ambient heat.
Replacing the Airtac SI125 Standard Cylinder SI125X400H with the SAI125X400H
To replace the SI125X400H, order the SAI125X400H. Verify the ISO 15552 mounting interface dimensions, the 125mm bore, the 400mm stroke, the G1/2 port (PT/G/NPT thread), and your specific mounting accessory. Because this SKU lacks a magnet, it cannot support CS1-B/DS1-B sensors; order an -S variant if position feedback is required. For sizing alternatives, a 100mm bore yields 3927N push at 0.5MPa, while a 160mm bore yields 10053N. At 400mm stroke, prevent rod bending by guiding the load externally to avoid side-load forces. Note that air cushions only decelerate the piston near stroke end; they do not hold the load. For secure holding without live air, specify an external pilot check valve or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X400H
- ✓ 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 SI125X400H FAQ
Yes, the AirTAC SI125X400H is discontinued. The direct replacement is the SAI125X400H. It is dimensionally interchangeable per the ISO 15552 mounting interface, retaining the same 125mm bore, 400mm stroke, 6136N force, G1/2 port, and mounting fixtures.
This 125mm bore double-acting cylinder features a G1/2 air port and a 32mm piston rod. The thrust ratings are 6136N push and 5734N pull at 0.5MPa, 8590N push at 0.7MPa, 11045N push at 0.9MPa, and a theoretical maximum of 1251kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X400H
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X400H replacement — usually within 7-8 hours.