This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X620, 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 SI125X620
The AirTAC SI125 Standard Cylinder SI125X620 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 620mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X620, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke620 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X620
- 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 SI125X620
The AirTAC SI125X620 is a discontinued double-acting ISO 15552 profile cylinder delivering 6136 N push force at 0.5 MPa. AirTAC replaced it with the SAI125X620 direct replacement, retaining the exact 125 mm bore, 620 mm stroke, G1/2 port, and ISO 15552 mounting interface. The SAI upgrade features an improved piston seal using two Y-shaped one-way elements for lower start-up pressure and longer life.
Without a -S suffix, this specific SKU cannot accept a magnetic sensor. The SAI family also introduces variants the SI lacked, like the SAIL air-released lock and BSAI clamp-lock. Rod material options include carbon steel, SUS420J2 (A), or SUS304 (B).
Airtac SI125 Standard Cylinder SI125X620 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X620 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X620 |
| Bore size | Ø125 mm |
| Stroke | 620 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 SAI125X620 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 SAI125X620 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 SI125X620
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×620 | 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 SI125X620 Is Used
Heavy Stamping Press
Drives large heavy-duty stamping operations where 6136 N of push force at 0.5 MPa is required to form thick metal components.
Pallet Diversion
Actuates heavy pallet routing gates on high-capacity assembly lines, utilizing the 620 mm stroke to clear wide loads safely.
Replacing the Airtac SI125 Standard Cylinder SI125X620 with the SAI125X620
To replace the SI125X620, order the SAI125X620. Verify your ISO 15552 mounting accessory (LB, FA, TC, etc.), the G1/2 port thread (PT, G, or NPT), and the M27x2 rod thread. If sizing up or down, neighboring bores are 100 mm and 160 mm; at 0.5 MPa, this 125 mm bore yields 6136 N push and 5734 N pull. Because the stroke is 620 mm, use an external guide to prevent rod bending and side-load damage. A plain cylinder drifts on air loss—the cushion only decelerates—so use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant for load holding. This non-magnet SKU cannot take a CS1-B/DS1-B sensor.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X620
- ✓ 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 SI125X620 FAQ
Yes, the SI125X620 is discontinued. The direct replacement is the AirTAC SAI125X620. It is dimensionally interchangeable per the ISO 15552 mounting interface, maintaining the same 125 mm bore, 620 mm stroke, output force, G1/2 port, and mounting accessories.
The G1/2 port is fixed by the 125 mm bore. 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; and a theoretical max of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X620
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X620 replacement — usually within 7-8 hours.