This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX70, 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 SI125BX70
The AirTAC SI125 Standard Cylinder SI125BX70 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 70mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX70, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke70 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX70
- 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 SI125BX70
The AirTAC SI125BX70 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 70 mm stroke. Delivering 6136 N push force at 0.5 MPa, it features a SUS304 stainless piston rod for corrosion resistance and a G1/2 air port. The direct replacement is the SAI125BX70, matching the bore, stroke, force, port and ISO 15552 mounting interface.
Upgrading to the SAI125BX70 retains all ratings but adds an upgraded piston seal using two Y-shaped one-way elements for low start-up pressure and long life. Note this SKU lacks a magnet (-S) and cannot take a sensor.
Airtac SI125 Standard Cylinder SI125BX70 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX70 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX70 |
| Bore size | Ø125 mm |
| Stroke | 70 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 SAI125BX70 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 SAI125BX70 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 SI125BX70
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×70 | 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 SI125BX70 Is Used
Heavy Stamping Press
Drives heavy stamping rams requiring 6136 N push force at 0.5 MPa, using the SUS304 rod to resist coolant corrosion.
Woodworking Clamp
Secures large timber beams during machining, utilizing the 125 mm bore's 5734 N pull force at 0.5 MPa.
Replacing the Airtac SI125 Standard Cylinder SI125BX70 with the SAI125BX70
To replace the SI125BX70, order the SAI125BX70. Verify the ISO 15552 mounting interface, 125 mm bore, 70 mm stroke, G1/2 port (PT/G/NPT thread options) and your mounting accessory. Because this SKU lacks a magnet, it cannot accept a CS1-B/DS1-B sensor; if sensing is needed, specify an SAI125X70S. Size both ways: neighbouring 100 mm bore yields 3927 N push at 0.5 MPa, while 160 mm yields 10053 N. A plain cylinder drifts on air loss—the cushion only decelerates—so for load holding use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants. The SAI family also adds the SAIF self-valve option (bores 32-100).
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX70
- ✓ 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 SI125BX70 FAQ
Yes, the SI125BX70 is discontinued. The direct replacement is the SAI125BX70, a current-production ISO 15552 cylinder with the same 125 mm bore, 70 mm stroke, G1/2 port and mounting interface. It fits existing fixtures perfectly.
The G1/2 port bore 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. The speed range is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX70
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX70 replacement — usually within 7-8 hours.