This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX35, 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 SI125BX35
The AirTAC Airtac SI125 Standard Cylinder SI125BX35 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 35mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX35, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke35 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX35
- 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 SI125BX35
The AirTAC SI125BX35 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 35 mm stroke. Built with an extruded aluminum barrel and adjustable air cushions, it delivers 6136 N push force at 0.5 MPa. The direct replacement is the SAI125BX35, retaining the exact same interface, port, and force. This specific SKU features a SUS304 stainless steel rod for corrosion resistance but lacks a magnet, meaning it cannot accept position sensors.
Upgrading to the SAI125BX35 introduces an improved piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Note that a standard cylinder cannot hold a load without live air; for locking needs, the SAI family offers SAIL and BSAI variants.
Airtac SI125 Standard Cylinder SI125BX35 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX35 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX35 |
| Bore size | Ø125 mm |
| Stroke | 35 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 SAI125BX35 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 SAI125BX35 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 SI125BX35
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×35 | 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 SI125BX35 Is Used
Heavy-Duty Pressing
Applies the 6136 N push force at 0.5 MPa to seat bearings or stamp components securely in automated machinery.
Pallet Diverting
Handles high-load lateral movement in conveyor lines, using the robust 32 mm SUS304 rod to push heavy pallets.
Clamp Actuation
Drives large machining clamps with a short 35 mm stroke, providing rigid holding force for metalworking fixtures.
Replacing the Airtac SI125 Standard Cylinder SI125BX35 with the SAI125BX35
To replace the discontinued SI125BX35, order the SAI125BX35, confirming the ISO 15552 mounting interface, 125 mm bore, 35 mm stroke, and G1/2 port. Because this SKU has no -S magnet, it cannot support legacy CS1-B/DS1-B sensors; if position detection is required, select an SAI model with a magnet. For sizing alternatives, a 100 mm bore provides 3927 N push at 0.5 MPa, while a 160 mm bore offers 10053 N. Remember that a plain cylinder drifts on air loss—the cushion only decelerates at stroke end—so use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant for held loads. The 35 mm stroke is short enough to avoid rod-bending concerns, but always guide the load to prevent side forces.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX35
- ✓ 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 SI125BX35 FAQ
Yes, the AirTAC SI125BX35 is discontinued. The direct replacement is the SAI125BX35. It is dimensionally interchangeable per ISO 15552, matching the 125 mm bore, 35 mm stroke, G1/2 port, and mounting interface, so it fits existing fixtures perfectly.
This 125 mm bore cylinder features a G1/2 air port and a 32 mm piston rod. It generates 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 maximum of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX35
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX35 replacement — usually within 7-8 hours.