This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX90STC, 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 SI125BX90STC
The AirTAC SI125 Standard Cylinder SI125BX90STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 90mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX90STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke90 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX90STC
- 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 SI125BX90STC
The AirTAC SI125BX90STC is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 90 mm stroke. It delivers 6136 N push force at 0.5 MPa, utilizing a SUS304 stainless piston rod (-B) for corrosion resistance and a TC trunnion mount. The direct replacement is the SAI125BX90STC, which preserves the G1/2 port, M27x2 thread, and ISO 15552 mounting interface.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. Note that a standard cylinder drifts without live air; for load holding, explore the SAIL or BSAI lock variants, or use an external pilot check valve.
Airtac SI125 Standard Cylinder SI125BX90STC Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX90STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX90STC |
| Bore size | Ø125 mm |
| Stroke | 90 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 SAI125BX90STC 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 SAI125BX90STC 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 SI125BX90STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×90 | 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 SI125BX90STC Is Used
Heavy Press Clamping
Secures large metal castings during machining operations, utilizing the 6136 N push force and robust TC trunnion mount to handle high side-load stresses on the fixture.
Bulk Material Diversion
Drives large-scale package diverters on high-throughput sorting lines, relying on the 30-500 mm/s speed range and adjustable 40 mm air cushions to prevent end-of-stroke impact.
Replacing the Airtac SI125 Standard Cylinder SI125BX90STC with the SAI125BX90STC
To replace the discontinued SI125BX90STC, order the SAI125BX90STC. Confirm the ISO 15552 TC trunnion interface, 125 mm bore, 90 mm stroke, G1/2 port, and the -S magnet for CS1-B/DS1-B sensors. The -B SUS304 rod is required for wet or corrosive settings. If sizing down, a 100 mm bore yields 3927 N push at 0.5 MPa; sizing up to 160 mm provides 10053 N. Remember that air cushions only decelerate the piston near stroke ends and do not hold loads—if power fails, use an external rod lock or the SAIL lock variant to prevent drifting.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX90STC
- ✓ 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 SI125BX90STC FAQ
Yes, the AirTAC SI125BX90STC is discontinued. The direct replacement is the SAI125BX90STC. It features the same ISO 15552 mounting interface, 125 mm bore, 90 mm stroke, G1/2 port, and TC trunnion mount, fitting directly into existing fixtures.
This 125 mm bore cylinder has a G1/2 air port. The thrust outputs 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, and a theoretical maximum of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX90STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX90STC replacement — usually within 7-8 hours.