This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125AX135, 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 SI125AX135
The AirTAC SI125 Standard Cylinder SI125AX135 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 135mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125AX135, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke135 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125AX135
- 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 SI125AX135
The AirTAC SI125AX135 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 135 mm stroke. Built with an extruded aluminum barrel, it delivers 6136 N push and 5734 N pull at 0.5 MPa, peaking at a 1251 kgf theoretical max. AirTAC replaced this legacy unit with the SAI125AX135 direct replacement, matching the exact G1/2 port, M27x2 rod thread, and ISO 15552 mounting interface.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. This specific SKU includes the SUS420J2 stainless steel rod (A suffix) for corrosion resistance but lacks a magnet, meaning it cannot accept CS1-B/DS1-B sensors. For load holding, note that standard air cushions only decelerate; explore the SAIL or BSAI lock variants.
Airtac SI125 Standard Cylinder SI125AX135 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125AX135 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125AX135 |
| Bore size | Ø125 mm |
| Stroke | 135 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 SAI125AX135 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 SAI125AX135 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 SI125AX135
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×135 | 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 SI125AX135 Is Used
Heavy Stamping Press
Drives heavy tooling with 6136 N push force at 0.5 MPa, utilizing the SUS420J2 stainless rod for corrosion resistance in harsh shop environments.
Large Component Clamp
Holds large fabricated parts during machining, taking advantage of the 125 mm bore's 1251 kgf theoretical max force at 1.0 MPa.
Replacing the Airtac SI125 Standard Cylinder SI125AX135 with the SAI125AX135
To replace the SI125AX135, order the SAI125AX135. Verify your ISO 15552 mounting fixtures (LB, FA, TC, etc.), the 135 mm stroke, and the G1/2 port. Because this SKU lacks the -S magnet, it cannot support position sensing; if switches are needed, select an SAI125X135S and use current AirTAC sensors. Sizing context: a 125 mm bore yields 6136 N push at 0.5 MPa, while a 100 mm bore offers 3927 N. For vertical loads, a plain cylinder drifts without live air—use an external pilot check valve or the SAIL/BSAI lock variants. Since the stroke is under 300 mm, rod bending risks are low, but always minimize side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125AX135
- ✓ 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 SI125AX135 FAQ
Yes, the SI125AX135 is discontinued. The direct replacement is the SAI125AX135. It shares the same ISO 15552 mounting interface, 125 mm bore, 135 mm stroke, G1/2 port, and output force, fitting existing fixtures perfectly.
This double-acting cylinder has a G1/2 port. It generates 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, 11045 N at 0.9 MPa, and a 1251 kgf theoretical max at 1.0 MPa. Speed range is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125AX135
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