This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X340S, 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 SI125X340S
The AirTAC SI125 Standard Cylinder SI125X340S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 340mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X340S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke340 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X340S
- 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 SI125X340S
The AirTAC SI125X340S is a discontinued double-acting ISO 15552 profile cylinder featuring a 125mm bore and 340mm stroke, delivering 6136 N push force at 0.5 MPa. It has a G1/2 port, M27x2 rod thread, and adjustable 40mm air cushions. Because the SI line is end-of-life, you should order the direct replacement: the SAI125X340S.
The SAI successor shares the exact ISO 15552 mounting interface, bore, stroke, and port, fitting existing fixtures perfectly. It upgrades the piston seal to two Y-shaped one-way elements for lower start-up pressure and longer life. Note that a plain cylinder drifts without air; for held loads use the SAIL or BSAI lock variants.
Airtac SI125 Standard Cylinder SI125X340S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X340S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X340S |
| Bore size | Ø125 mm |
| Stroke | 340 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 SAI125X340S 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 SAI125X340S 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 SI125X340S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×340 | 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 SI125X340S Is Used
Heavy Stamping Press
Drives large platens in metal forming, using the 6136 N thrust to actuate heavy tooling through the 340mm travel.
Bulk Material Diversion
Actuates large-scale lane changers and diverters on high-capacity packaging lines with reliable 30-500 mm/s speed.
Replacing the Airtac SI125 Standard Cylinder SI125X340S with the SAI125X340S
To replace the SI125X340S, order the SAI125X340S, verifying the ISO 15552 mounting interface, G1/2 port, and the -S magnet for CS1-B/DS1-B switches (the SAI uses current AirTAC switches). If you need more force than the 6136 N at 0.5 MPa, step up to a 160mm bore; if less is required, a 100mm bore provides 3927 N. Because the 340mm stroke exceeds 300mm, use external guides to prevent rod bending and side-load damage. A standard cylinder does not hold load on air loss—the cushion only decelerates—so specify the SAIL lock, BSAI clamp-lock, or an external pilot check valve if load holding is required.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X340S
- ✓ 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 SI125X340S FAQ
Yes, the SI125X340S is discontinued. The direct replacement is the AirTAC SAI125X340S. It is dimensionally interchangeable per ISO 15552, retaining the same 125mm bore, 340mm stroke, output force, G1/2 port, and mounting accessories, so it fits existing fixtures directly.
This double-acting cylinder features a G1/2 air port and M27x2 rod thread. The thrust 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 maximum of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X340S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X340S replacement — usually within 7-8 hours.