This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX135, 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 SI125BX135
The AirTAC SI125 Standard Cylinder SI125BX135 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 SAI125BX135, 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 → SAI125BX135
- 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 SI125BX135
The AirTAC SI125BX135 is a discontinued double-acting ISO 15552 profile cylinder featuring a 125 mm bore, 135 mm stroke, and a SUS304 stainless steel piston rod. It delivers 6136 N push force at 0.5 MPa. AirTAC replaced this legacy unit with the SAI125BX135, a direct sharing the exact ISO 15552 mounting interface, G1/2 port, and output force.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and longevity. Note this SKU lacks a magnet, so it cannot accept CS1-B/DS1-B sensors. The SAI family also adds SAIL and BSAI lock variants absent in the SI line.
Airtac SI125 Standard Cylinder SI125BX135 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX135 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX135 |
| 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 SAI125BX135 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 SAI125BX135 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 SI125BX135
| 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 SI125BX135 Is Used
Heavy Stamp Press Feed
Drives robust 313 kg vertical lifts in stamping lines, utilizing the 6136 N thrust at 0.5 MPa to move heavy billets into the press bed.
Pallet Dispenser Gate
Actuates heavy-duty pallet flow gates in high-throughput logistics hubs, where the 125 mm bore handles substantial inertial loads reliably.
Injection Mold Clamp
Secures large injection molding tooling halves using the SUS304 rod for corrosion resistance in humid production environments.
Replacing the Airtac SI125 Standard Cylinder SI125BX135 with the SAI125BX135
To replace the SI125BX135, order the SAI125BX135. Verify your ISO 15552 mounting fixture (LB, FA, TC, etc.), the 135 mm stroke, and the G1/2 port. This unit uses a SUS304 stainless rod; if corrosion is not a concern, the standard carbon steel rod is fine. Because this SKU has no magnet (-S), it cannot support position sensing—order a magnet-equipped SAI if you need CS1-B/DS1-B switches. For loads near the 11045 N @0.9 MPa limit, consider the 160 mm bore. A plain cylinder drifts without air; for load holding, use an external pilot check valve or the SAIL/BSAI lock variants. Since the stroke is 135 mm, ensure adequate guide support to prevent rod bending under side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX135
- ✓ 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 SI125BX135 FAQ
Yes, the AirTAC SI125BX135 is discontinued. The direct replacement is the SAI125BX135. It shares the same ISO 15552 mounting interface, 125 mm bore, 135 mm stroke, G1/2 port, and output force, fitting directly into your existing fixtures.
It features a G1/2 air port and M27x2 rod thread. Force ratings are: 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; with a theoretical maximum of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX135
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX135 replacement — usually within 7-8 hours.