This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAIJ125X500-20S, 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 SIJ125X500-20S
The AirTAC SIJ125 Double Rod Adjustable Cylinder SIJ125X500-20S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 500mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAIJ125X500-20S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke500 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAIJ125X500-20S
- 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 SIJ125X500-20S
The AirTAC SIJ125X500-20S is a double-acting double-rod ISO 15552 adjustable-stroke cylinder, now discontinued and replaced by the direct replacement SAIJ125X500-20S. The external stop screw lets you trim the extend stroke by up to 20 mm on-site, yielding a usable 480-500 mm stroke (500 mm nominal maximum). It features a 125 mm bore, G1/2 port, M27x2 rod thread, and 40 mm adjustable cushions. The stop sets the end position but is not a load lock.
The SAIJ replacement retains the exact interface and force, but upgrades to a two Y-shaped one-way piston seal for lower start-up pressure and longer life. The -S suffix indicates a piston magnet for legacy CS1-B/DS1-B sensors.
Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X500-20S Technical Specifications
| Model | Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X500-20S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAIJ125X500-20S |
| Bore size | Ø125 mm |
| Stroke | 500 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 SAIJ125X500-20S 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 SAIJ125X500-20S 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 SIJ125X500-20S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×500 | 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 SIJ125X500-20S Is Used
Press Fit Tuning
Needs field stroke tuning to dial in the exact 480-500 mm extend position for seating heavy bearings without over-traveling.
Heavy Lift Gate
Uses the external screw to set the precise end position for a 313 kg vertical lift load, ensuring consistent placement.
Replacing the Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X500-20S with the SAIJ125X500-20S
To replace the discontinued SIJ125X500-20S, order the direct replacement SAIJ125X500-20S, which preserves the ISO 15552 mounting interface, 500 mm stroke, 20 mm adjust window, and G1/2 port. Choose the 20 mm adjust window if your application requires fine-tuning the extend end position within a 480-500 mm range. FA, LB, and TC mountings are available. Because the 500 mm stroke is long, verify side-load limits and use external guides to prevent rod bending. The -S magnet enables position sensing. Remember the stop screw is not a lock; for load holding on air loss, use an external rod lock, pilot-operated check valve, or SAIL/BSAI variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAIJ125X500-20S
- ✓ 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 SIJ125X500-20S FAQ
Yes, the SIJ125X500-20S is discontinued. The direct replacement is the SAIJ125X500-20S, offering the same ISO 15552 interface, 125 mm bore, 500 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 on-site from 500 mm down to 480 mm. The stop sets end position and is not a load lock.
Related AirTAC SAI Cylinders
Request a Quote for the SAIJ125X500-20S
Send us the quantity and destination. We confirm price, stock and lead time on the SAIJ125X500-20S replacement — usually within 7-8 hours.