This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X273, 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 SI125X273
The AirTAC SI125 Standard Cylinder SI125X273 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 273mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X273, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke273 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X273
- 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 SI125X273
The AirTAC SI125X273 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 273 mm stroke. It delivers 6136 N push force at 0.5 MPa. The direct replacement is the SAI125X273, matching the interface, force, G1/2 port and mounting. This 273 mm stroke is nonstandard. As this SKU lacks the -S magnet, it cannot accept a sensor.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure. It also adds SAIL, SAIF and BSAI variants the SI lacked. Note a plain cylinder drifts without air; use SAIL or a check valve to hold loads.
Airtac SI125 Standard Cylinder SI125X273 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X273 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X273 |
| Bore size | Ø125 mm |
| Stroke | 273 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 SAI125X273 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 SAI125X273 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 SI125X273
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×273 | 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 SI125X273 Is Used
Heavy Pressing
Drives large stamping or forming presses requiring 6136 N push force at 0.5 MPa with stable ISO 15552 fixture mounting.
Bulk Diverting
Diverts heavy bulk goods on conveyors, utilizing the 125 mm bore and adjustable 40 mm air cushions to stop smoothly.
Replacing the Airtac SI125 Standard Cylinder SI125X273 with the SAI125X273
To replace the SI125X273, order the SAI125X273. Verify the ISO 15552 mounting interface, 125 mm bore, 273 mm nonstandard stroke, G1/2 port (PT/G/NPT), and accessories. This no-magnet SKU cannot take a sensor; order -S for CS1-B/DS1-B switches. For load holding, the cushion only decelerates; use a SAIL lock, BSAI clamp-lock, or external pilot check valve. Neighbouring bores: 100 mm gives 3927 N [email protected], 160 mm gives 10053 N. For this 273 mm stroke, ensure guide rails to prevent rod bending under side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X273
- ✓ 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 SI125X273 FAQ
Yes, the SI125X273 is discontinued. The direct replacement is the SAI125X273. It is dimensionally interchangeable per ISO 15552, keeping the same 125 mm bore, 273 mm stroke, force, G1/2 port and mounting.
It features a G1/2 port, M27x2 rod thread, and 40 mm cushions. Force output is 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 max of 1251 kgf at 1.0 MPa. Speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X273
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X273 replacement — usually within 7-8 hours.