
The AirTAC SAIJ125 Adjustable Cylinder SAIJ125X400-20S is a genuine double-acting ISO 15552 profile-barrel air cylinder with a Ø125mm bore and 400mm stroke, G1/2 air ports and adjustable end cushioning. Its standardized mounting interface makes it interchangeable with other ISO 15552 cylinders at the mounting interface.
The AirTAC SAIJ125X400-20-S is a double-acting ISO 15552 profile cylinder featuring a rear-mounted stroke adjuster. With a 400 mm nominal stroke and a 20 mm adjustment range, it provides a usable travel window of 380 to 400 mm. This built-in adjustability allows you to fine-tune the retract end-position at commissioning without adding external stops or swapping the cylinder.
Equipped with a -S magnet, this model integrates seamlessly with AirTAC CMSE reed and DMSE electronic solid-state sensors housed in the dual-side sensor grooves. The extruded aluminum barrel design omits tie-rods, and the mounting set is limited to Basic, FA, LB, TC, FTC, TCM1, and TCM2. The 32 mm carbon steel rod and M27x2 thread provide robust load-bearing capability, while the PT tapered ports ensure a reliable pneumatic seal.
| Model | Airtac SAIJ125 Adjustable Cylinder SAIJ125X400-20S |
|---|---|
| Series | SAI ISO 15552 profile cylinder |
| Bore size | Ø125 mm |
| Stroke | 400 mm |
| Acting type | Double acting |
| Port size | G1/2 |
| Rod thread | M27×2 |
| 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 stroke | Up to 1500 mm |
Specifications follow the official AirTAC SAI series datasheet and ISO 15552 dimensions. Confirm against the product label before installation. Port options: G (BSPP) / NPT.
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 5734 N | 5734 N |
| 0.7 MPa | 8027 N | — |
| Max (@1.0 MPa) | 1169 kgf | |
Double-rod model: the rod passes through the rear cover, so both piston faces lose rod area and push is shown at the annular-area value. Actual usable force is lower than theoretical due to friction and back-pressure. Size with a safety margin.
| SAI | ISO 15552 profile-barrel cylinder series. |
|---|---|
| 125 | Bore size in mm. |
| ×400 | Stroke length in mm. |
| -S | Optional built-in magnet for sensor position sensing. |
Related SAI-family variants: SAID (double rod), SAIJ (adjustable stroke), SAIL (with lock), SAIF (with valve), BSAI (enclasp / clamp-lock), and SAI-S with built-in magnet. Rod material: carbon steel (blank) / SUS420J2 (A) / SUS304 (B); seals: TPU (blank) / Viton H / NBR N.
Dial in the exact retract position within the 380-400 mm window during product size changes without physically swapping cylinders or repositioning external stop blocks.
Fine-tune the end-of-stroke location on diverter mechanisms by up to 20 mm at commissioning to perfectly synchronize with downstream conveyor feeds.
The adjustable stroke is ideal for product changeovers on a line, allowing the retract end-stop to be dialed back by up to 20 mm without mechanical modifications. When replacing an ISO 15552 cylinder, match the 125 mm bore, 400 mm stroke, 20 mm adjustment, PT port thread, and the -S magnet requirement.
Because the total stroke is 400 mm, the long unsupported rod is susceptible to side-loading; an external guide rail should be used to prevent premature seal wear. Note that the rear adjuster acts only as a travel stop and does not hold the load without live air. For dead-load holding, consider the SAIL (air-released lock) or BSAI (clamp-lock) variants.
Quick checklist
At 0.7 MPa, the push force increases to 8590 N.
The rear adjuster screw allows you to shorten the effective travel by up to 20 mm. This creates a 380 to 400 mm usable stroke window, enabling fine-tuning of the end position without changing the cylinder.
Genuine AirTAC parts produced by AirTAC factory.
Covers non-human-caused product damage.
Standard models are processed and dispatched in 3-5 business days.
Most inquiries answered within 7-8 hours.
Send us the quantity and destination. We confirm price, stock and lead time — usually within 7-8 hours.