This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAIJ125X450-20S, 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 SIJ125 Double Rod Adjustable Cylinder SIJ125X450-20S
The AirTAC SIJ125 Double Rod Adjustable Cylinder SIJ125X450-20S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 450mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAIJ125X450-20S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke450 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAIJ125X450-20S
- 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 SIJ125 Double Rod Adjustable Cylinder SIJ125X450-20S
The AirTAC SIJ125X450-20S is a discontinued double-acting double-rod adjustable-stroke ISO 15552 cylinder. An external stop screw lets you trim the extend stroke by up to 20 mm on-site, yielding a usable 430-450 mm stroke (450 mm is the maximum). The direct replacement is the SAIJ125X450-20S.
The SAIJ successor reuses the ISO 15552 mounting interface and adds an upgraded two-piece Y-shaped piston seal for lower start-up pressure. The -S suffix provides a piston magnet for legacy CS1-B/DS1-B switches. The stop screw sets end position only; it is not a load lock.
Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X450-20S Technical Specifications
| Model | Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X450-20S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAIJ125X450-20S |
| Bore size | Ø125 mm |
| Stroke | 450 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 SAIJ125X450-20S 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 SAIJ125X450-20S produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X450-20S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×450 | 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 SIJ125 Double Rod Adjustable Cylinder SIJ125X450-20S Is Used
Press Fit Tuning
Trimming the extend stroke by up to 20 mm on-site allows precise bottoming force for press-fitting bearings without machining custom spacers.
Transfer Stopper Adjustment
External stop screw provides 430-450 mm positioning to fine-tune product halt locations on varying-width conveyor lines.
Carton Sealing Alignment
Field-adjusting the extend end position compensates for minor carton size variations, ensuring consistent flap folding pressure.
Replacing the Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X450-20S with the SAIJ125X450-20S
To replace the discontinued SIJ125X450-20S, order the direct replacement SAIJ125X450-20S, keeping the 450 mm stroke, 20 mm adjust window, and G1/2 port. Select the 20 mm adjust window if you need 430-450 mm end-position tuning; it cannot lock a load. Mounting options include FA, LB, and TC. The -S magnet enables legacy CS1-B/DS1-B sensors. Because the 450 mm stroke exceeds 300 mm, account for side-load and rod-bending by using external guides to prevent premature wear.
Replacement checklist
- ✓ Same ISO 15552 interface → SAIJ125X450-20S
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X450-20S FAQ
Yes, the SIJ125X450-20S is discontinued. The direct replacement is the SAIJ125X450-20S, offering the same ISO 15552 interface, 125 mm bore, 450 mm stroke, 20 mm adjust window, and G1/2 port.
The external stop screw window is 20 mm, allowing the extend stroke to be shortened from 450 mm down to 430 mm. This stop sets end position only and is not a load lock.
Related AirTAC SAI Cylinders
Request a Quote for the SAIJ125X450-20S
Send us the quantity and destination. We confirm price, stock and lead time on the SAIJ125X450-20S replacement — usually within 7-8 hours.