This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAIJ125X400-50, 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 SIJ125X400-50
The AirTAC SIJ125 Double Rod Adjustable Cylinder SIJ125X400-50 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 400mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAIJ125X400-50, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke400 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAIJ125X400-50
- 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 SIJ125X400-50
The AirTAC SIJ125X400-50 is a discontinued double-acting double-rod ISO 15552 adjustable-stroke cylinder with a 125 mm bore and 400 mm maximum stroke. An external stop screw lets you trim the extend stroke by up to 50 mm on-site, yielding a usable 350-400 mm extension window. The stop screw strictly sets the end position; it is not a load lock, and a plain cylinder does not hold loads on air loss. The direct replacement is the SAIJ125X400-50, matching the G1/2 port, M27x2 rod thread, and 40 mm adjustable cushions.
Upgrading to the SAIJ family brings a superior two-piece Y-shaped piston seal for lower start-up pressure, and introduces lock variants like SAIL and BSAI absent from the legacy SI line. This non-magnet SKU cannot accept position sensors.
Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X400-50 Technical Specifications
| Model | Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X400-50 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAIJ125X400-50 |
| Bore size | Ø125 mm |
| Stroke | 400 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 SAIJ125X400-50 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 SAIJ125X400-50 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 SIJ125X400-50
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×400 | 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 SIJ125X400-50 Is Used
Press Fit Tuning
Final insertion depth of bearings or pins often requires field stroke tuning; the 50 mm adjust window lets operators trim the extend stroke on-site to hit exact pressing positions without changing the cylinder body.
Variable Height Sealing
Carton sealing or palletizing tasks dealing with fluctuating package heights benefit from the 350-400 mm usable extend window, allowing the external stop screw to set the precise sealing height for each run.
Replacing the Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X400-50 with the SAIJ125X400-50
To replace the discontinued SIJ125X400-50, order the direct replacement SAIJ125X400-50, retaining the exact ISO 15552 mounting interface and 50 mm adjust window. Choose the 50 mm adjust window if your end-position tuning requires up to a 50 mm extend trim. Mounting options include FA, LB, and TC brackets. Because this SKU lacks the -S magnet, it cannot accept legacy CS1-B or DS1-B sensors. Finally, at the 400 mm stroke length, account for side-load and rod-bending forces by utilizing external guides to prevent premature wear.
Replacement checklist
- ✓ Same ISO 15552 interface → SAIJ125X400-50
- ✓ 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 SIJ125X400-50 FAQ
Yes, the SIJ125X400-50 is discontinued. The direct replacement is the SAIJ125X400-50, which matches the ISO 15552 interface, 125 mm bore, 400 mm stroke, 50 mm adjust window, G1/2 port, and mounting options. The SAIJ upgrade also features a two-piece Y-shaped piston seal for lower start-up pressure.
The external stop screw provides a 50 mm adjust window, allowing you to trim the extend stroke from the 400 mm maximum down to 350 mm. The stop sets end position only and is not a load lock.
Related AirTAC SAI Cylinders
Request a Quote for the SAIJ125X400-50
Send us the quantity and destination. We confirm price, stock and lead time on the SAIJ125X400-50 replacement — usually within 7-8 hours.