This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X320, 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 SI125X320
The AirTAC SI125 Standard Cylinder SI125X320 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 320mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X320, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke320 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X320
- 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 SI125X320
The AirTAC SI125X320 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 320 mm stroke. Delivering 6136 N push force at 0.5 MPa, it features a G1/2 port, M27x2 rod thread, and 40 mm adjustable air cushions. The direct replacement is the SAI125X320, which matches the exact ISO 15552 mounting interface, bore, stroke, force, and port size.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. Note this non-magnet SKU cannot accept a sensor; legacy -S versions used CS1-B/DS1-B switches. For high heat, Viton H seals raise the temperature limit to 150 C.
Airtac SI125 Standard Cylinder SI125X320 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X320 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X320 |
| Bore size | Ø125 mm |
| Stroke | 320 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 SAI125X320 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 SAI125X320 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 SI125X320
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×320 | 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 SI125X320 Is Used
Heavy Press Operations
Ideal for applying high clamping forces in automated stamping and metal forming lines, utilizing the 6136 N push force at 0.5 MPa.
Pallet Positioning
Moves heavy loaded pallets along conveyors, where the 313 kg vertical lift capacity and 320 mm stroke provide robust actuation.
Large Fixture Actuation
Shifts substantial machining fixtures into position, benefiting from the 40 mm adjustable cushions to decelerate heavy masses smoothly.
Replacing the Airtac SI125 Standard Cylinder SI125X320 with the SAI125X320
To replace the SI125X320, order the SAI125X320 direct. Verify the ISO 15552 mounting accessory (LB, FA, TC, etc.), the G1/2 port thread (PT, G, or NPT), and the M27x2 rod end. Because this SKU lacks the -S magnet, it cannot support position sensing. If sizing up or down, neighboring bores are 100 mm (3927 N push @0.5 MPa) and 160 mm (10053 N push @0.5 MPa). The 320 mm stroke requires external guides to prevent rod bending under side loads. A plain cylinder drifts on air loss; for load holding, use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X320
- ✓ 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 SI125X320 FAQ
Yes, the AirTAC SI125X320 is discontinued. The direct replacement is the SAI125X320. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 320 mm stroke, G1/2 port, and mounting interface.
This double-acting cylinder features a G1/2 port. It 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 maximum of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X320
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X320 replacement — usually within 7-8 hours.