This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAIJ125X55-20, 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 SIJ125X55-20
The AirTAC SIJ125 Double Rod Adjustable Cylinder SIJ125X55-20 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 55mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAIJ125X55-20, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke55 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAIJ125X55-20
- 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 SIJ125X55-20
The AirTAC SIJ125X55-20 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, yielding a usable 35-55 mm range from the 55 mm nominal maximum. The direct replacement is the SAIJ125X55-20, matching the interface, force, and mounting.
The SAIJ upgrade introduces a two Y-shaped one-way piston seal for lower start-up pressure and longer life. Note this SKU lacks a -S magnet and cannot take a switch. The stop screw sets end position only; it is not a load lock, so use an external rod lock or SAIL/BSAI variant for held loads.
Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X55-20 Technical Specifications
| Model | Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X55-20 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAIJ125X55-20 |
| Bore size | Ø125 mm |
| Stroke | 55 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 SAIJ125X55-20 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 SAIJ125X55-20 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 SIJ125X55-20
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×55 | 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 SIJ125X55-20 Is Used
Press Fit Tuning
Dialing in a precise insertion depth on-site without machining custom spacers, using the 20 mm adjust window to find the exact press fit.
Variable Height Sealing
Accommodating different carton heights on a packaging line by tweaking the extend endpoint within the 35-55 mm usable range.
Replacing the Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X55-20 with the SAIJ125X55-20
To replace the discontinued SIJ125X55-20, order the direct replacement SAIJ125X55-20, reusing your existing FA, LB, or TC ISO 15552 mounts. The 20 mm adjust window is ideal if your end-position target falls between 35 and 55 mm. Because this SKU lacks the -S magnet, it cannot accept legacy CS1-B/DS1-B sensors; add external detection if needed. For strokes at or above 300 mm, verify your guide structure to manage side-load moments. Remember the stop screw is not a brake; for load holding on air loss, specify a SAIL or BSAI lock variant or an external pilot-operated check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAIJ125X55-20
- ✓ 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 SIJ125X55-20 FAQ
Yes, the SIJ125X55-20 is discontinued. The direct replacement is the SAIJ125X55-20. It shares the identical ISO 15552 interface, 125 mm bore, 55 mm stroke, 20 mm adjust window, G1/2 port, and mounting, but adds an upgraded two Y-shaped one-way piston seal.
The external stop screw trims the extend stroke by up to 20 mm on-site, giving a usable 35-55 mm range. The stop sets end position and is not a load lock.
Related AirTAC SAI Cylinders
Request a Quote for the SAIJ125X55-20
Send us the quantity and destination. We confirm price, stock and lead time on the SAIJ125X55-20 replacement — usually within 7-8 hours.