This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X355, 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 SI125X355
The AirTAC Airtac SI125 Standard Cylinder SI125X355 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 355mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X355, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke355 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X355
- 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 SI125X355
The AirTAC SI125X355 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 355 mm stroke. Delivering 6136 N push force at 0.5 MPa through a G1/2 port, it is replaced by the SAI125X355. This direct successor shares the exact ISO 15552 mounting interface, bore, stroke, force, port and mounting hardware.
The SAI upgrade features a revised piston seal with two Y-shaped one-way elements for low start-up pressure and long life. For sensing, note this specific SI SKU lacks a magnet and cannot accept a switch. The SAI family also introduces SAIL, SAIF and BSAI lock variants absent in the SI line.
Airtac SI125 Standard Cylinder SI125X355 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X355 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X355 |
| Bore size | Ø125 mm |
| Stroke | 355 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 SAI125X355 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 SAI125X355 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 SI125X355
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×355 | 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 SI125X355 Is Used
Heavy Press Clamping
Secures large metal castings during machining, utilizing the 6136 N push force at 0.5 MPa to hold components firmly under heavy tooling loads.
Bulk Material Diversion
Drives large-scale package diverters on high-throughput sorting lines, with the 355 mm stroke providing the reach needed to clear wide conveyor belts.
Replacing the Airtac SI125 Standard Cylinder SI125X355 with the SAI125X355
To replace the SI125X355, order the SAI125X355. Confirm the ISO 15552 mounting interface, 125 mm bore, 355 mm stroke, G1/2 port (PT/G/NPT thread options), and your mounting accessory (LB, FA, FB, CA, CB, TC, etc.). This SKU has no magnet (-S), so it cannot accept CS1-B/DS1-B sensors; order a magnet-equipped SAI if position detection is needed. Neighbouring bores are 100 mm (3927 N push @0.5 MPa) and 160 mm (10053 N push @0.5 MPa). Because the 355 mm stroke is long, use an external guide to prevent rod bending and side-load wear. The air cushion (40 mm) only decelerates; for load holding on air loss, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X355
- ✓ 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 SI125X355 FAQ
Yes, the AirTAC SI125X355 is discontinued. The direct replacement is the SAI125X355. It shares the same ISO 15552 mounting interface, 125 mm bore, 355 mm stroke, output force, G1/2 port and mounting accessories, fitting directly into existing fixtures.
This double-acting cylinder has a 125 mm bore, 32 mm rod, M27x2 thread, G1/2 port, 40 mm cushion, and operates at 30-500 mm/s. Force ratings are: push 6136 N and pull 5734 N at 0.5 MPa, push 8590 N at 0.7 MPa, push 11045 N at 0.9 MPa, and a theoretical max of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X355
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X355 replacement — usually within 7-8 hours.