This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAIJ125X400-50S, 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 SIJ125X400-50S
The AirTAC SIJ125 Double Rod Adjustable Cylinder SIJ125X400-50S 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 SAIJ125X400-50S, 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 → SAIJ125X400-50S
- 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 SIJ125X400-50S
The AirTAC SIJ125X400-50S is a discontinued double-acting double-rod ISO 15552 adjustable-stroke cylinder with a 125 mm bore and 400 mm nominal 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. The direct replacement is the SAIJ125X400-50S, sharing the exact interface, force, and adjust window.
The SAIJ upgrade introduces an improved two-piece Y-shaped piston seal for lower start-up pressure and longer life. Note that the external stop sets end position but is not a load lock; for held loads use an external rod lock or SAIL/BSAI variant.
Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X400-50S Technical Specifications
| Model | Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X400-50S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAIJ125X400-50S |
| 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 SAIJ125X400-50S 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 SAIJ125X400-50S 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 SIJ125X400-50S
| 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 SIJ125X400-50S Is Used
Press Fit Tuning
Allows operators to dial in the exact 350-400 mm extend position for pressing bearings without swapping fixed-stop cylinders.
Variable Length Diverter
Adjusts the extend stroke on-site by up to 50 mm to accommodate changing package sizes on a sorting line.
Adjustable Pallet Stop
Provides a field-tunable hard stop for pallets of varying depths, ensuring precise positioning before wrapping.
Replacing the Airtac SIJ125 Double Rod Adjustable Cylinder SIJ125X400-50S with the SAIJ125X400-50S
To replace the discontinued SIJ125X400-50S, order the direct replacement SAIJ125X400-50S, which preserves the 50 mm adjust window, 400 mm max stroke, G1/2 port, and ISO 15552 mounting. The 50 mm adjust window is ideal for fine-tuning the extend endpoint without machining. Mounting options include FA, LB, and TC. The -S suffix provides a piston magnet for CS1-B/DS1-B switches. Because the 400 mm stroke is long, verify side-load limits and use external guides to prevent rod bending.
Replacement checklist
- ✓ Same ISO 15552 interface → SAIJ125X400-50S
- ✓ 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 SIJ125X400-50S FAQ
Yes, the SIJ125X400-50S is discontinued. The direct replacement is the SAIJ125X400-50S, which matches the 125 mm bore, 400 mm stroke, 50 mm adjust window, G1/2 port, and ISO 15552 mounting.
The external stop screw allows trimming the extend stroke by up to 50 mm on-site.
Related AirTAC SAI Cylinders
Request a Quote for the SAIJ125X400-50S
Send us the quantity and destination. We confirm price, stock and lead time on the SAIJ125X400-50S replacement — usually within 7-8 hours.