This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAIJ125X50-20S, 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 SIJ125X50-20S
The AirTAC SIJ125 Double Rod Adjustable Cylinder SIJ125X50-20S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 50mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAIJ125X50-20S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke50 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAIJ125X50-20S
- 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 SIJ125X50-20S
The AirTAC SIJ125X50-20S is a discontinued double-acting double-rod ISO 15552 adjustable-stroke cylinder. An external stop screw lets you trim the extend stroke by up to 20 mm on-site, giving a usable 30-50 mm extend window from the 50 mm nominal maximum. The direct replacement is the SAIJ125X50-20S, matching the interface, force, and mounting.
The SAIJ successor retains ISO 15552 mounting reuse and adds an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. It also introduces SAIL and BSAI lock variants absent in the SI line. Note the stop screw sets end position only; it is not a load lock.
Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X50-20S Technical Specifications
| Model | Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X50-20S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAIJ125X50-20S |
| Bore size | Ø125 mm |
| Stroke | 50 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 SAIJ125X50-20S 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 SAIJ125X50-20S 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 SIJ125X50-20S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×50 | 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 SIJ125X50-20S Is Used
Press Fit Tuning
Dialing in a 30-50 mm press insertion for bearings, where the 20 mm external stop screw allows exact field stroke tuning without swapping cylinders.
Variable Height Sealing
Adjusting a sealing head on the fly for mixed product runs, using the 125 mm bore's 5734 N pull at 0.5 MPa to secure film clamps.
Replacing the Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X50-20S with the SAIJ125X50-20S
To replace the discontinued SIJ125X50-20S, order the direct replacement SAIJ125X50-20S, keeping the 50 mm nominal stroke, 20 mm adjust window, and -S magnet for CS1-B/DS1-B switches. Choose the 20 mm adjust window when you need precise 30-50 mm extend tuning. Mounting options include FA, LB, and TC. Because the 50 mm stroke is under 300 mm, side-load lever arm concerns are minimal. The external stop sets end position but does not lock; for load holding on air loss, use an external rod lock or SAIL/BSAI variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAIJ125X50-20S
- ✓ 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 SIJ125X50-20S FAQ
Yes, the SIJ125X50-20S is discontinued. The direct replacement is the SAIJ125X50-20S. It shares the identical ISO 15552 interface, 125 mm bore, 50 mm stroke, 20 mm adjust window, G1/2 port, and mounting, but adds an upgraded piston seal.
The external stop screw provides a 20 mm adjust window, allowing you to shorten the 50 mm nominal extend stroke down to 30 mm on-site. The stop sets end position only and is not a load lock.
Related AirTAC SAI Cylinders
Request a Quote for the SAIJ125X50-20S
Send us the quantity and destination. We confirm price, stock and lead time on the SAIJ125X50-20S replacement — usually within 7-8 hours.