This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAIJ125X40-20S, 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 SIJ125X40-20S
The AirTAC SIJ125 Double Rod Adjustable Cylinder SIJ125X40-20S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 40mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAIJ125X40-20S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke40 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAIJ125X40-20S
- 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 SIJ125X40-20S
The AirTAC SIJ125X40-20S is a double-acting double-rod ISO 15552 adjustable-stroke cylinder, now discontinued. It features a 125 mm bore, a 40 mm nominal stroke, and a built-in piston magnet (-S) for legacy CS1-B/DS1-B switches. An external stop screw lets you trim the extend stroke by up to 20 mm on-site, yielding a usable extend range of 20-40 mm. The stop sets the end position but is not a load lock.
The direct replacement is the SAIJ125X40-20S, preserving the ISO 15552 mounting interface, bore, force, and port. The SAIJ upgrade introduces a two Y-shaped one-way piston seal for lower start-up pressure and longer life. Remember, a plain cylinder drifts on air loss; use an external rod lock or SAIL/BSAI variant for held loads.
Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X40-20S Technical Specifications
| Model | Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X40-20S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAIJ125X40-20S |
| Bore size | Ø125 mm |
| Stroke | 40 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 SAIJ125X40-20S 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 SAIJ125X40-20S 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 SIJ125X40-20S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×40 | 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 SIJ125X40-20S Is Used
Press Fit Tuning
Allows operators to dial in the exact 20-40 mm extend position for seating bearings without machining hard stops.
Variable Height Sealing
Adjusts the crush height on carton sealing heads on-site, accommodating different flute thicknesses.
Short-Stroke Clamping
Provides 6136 N of clamping force at 0.5 MPa where the exact jaw closure point must be tweaked.
Replacing the Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X40-20S with the SAIJ125X40-20S
To replace the discontinued SIJ125X40-20S, order the direct replacement SAIJ125X40-20S, which matches the ISO 15552 dimensions, G1/2 port, M27x2 rod thread, and 20 mm adjust window. Choose the 20 mm adjust window if your fixture requires precise on-site extend tuning between 20 and 40 mm. Reuse FA, LB, or TC mounts directly. The -S suffix ensures a piston magnet for legacy CS1-B/DS1-B sensors (the SAIJ uses current AirTAC switches). Because the 40 mm stroke is under 300 mm, side-load rod deflection is minimal, but always guide the load externally.
Replacement checklist
- ✓ Same ISO 15552 interface → SAIJ125X40-20S
- ✓ 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 SIJ125X40-20S FAQ
Yes, the SIJ125X40-20S is discontinued. The direct replacement is the SAIJ125X40-20S. It shares the same ISO 15552 interface, 125 mm bore, 40 mm stroke, 20 mm adjust window, G1/2 port, and mounting options. The SAIJ upgrade features a two Y-shaped one-way piston seal for longer life.
The external stop screw window is 20 mm, allowing you to trim the 40 mm nominal extend stroke down to 20 mm on-site. The stop sets end position and is not a load lock.
Related AirTAC SAI Cylinders
Request a Quote for the SAIJ125X40-20S
Send us the quantity and destination. We confirm price, stock and lead time on the SAIJ125X40-20S replacement — usually within 7-8 hours.