Airtac SAIJ125 Adjustable Cylinder SAIJ125X425-20S
The AirTAC Airtac SAIJ125 Adjustable Cylinder SAIJ125X425-20S is a genuine double-acting ISO 15552 profile-barrel air cylinder with a Ø125mm bore and 425mm stroke, G1/2 air ports and adjustable end cushioning. Its standardized mounting interface makes it a drop-in replacement for other ISO 15552 cylinders in automation lines.
- BoreØ125 mm
- Stroke425 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2
- CushionAdjustable, 40 mm
About the Airtac SAIJ125 Adjustable Cylinder SAIJ125X425-20S
The AirTAC SAIJ125X425-20-S is a double-acting ISO 15552 profile cylinder equipped with a rear stroke adjuster, providing a usable travel window of 405 to 425 mm. It delivers 6136 N of push force at 0.5 MPa, making it suitable for heavy-duty positioning tasks. The integrated magnet supports position sensing via AirTAC CMSE reed and DMSE electronic switches.
This model features a carbon steel piston rod with an M27x2 thread and PT tapered ports. The extruded aluminum barrel incorporates sensor grooves on both sides. You can fine-tune the retract end-position at commissioning without swapping the cylinder or adding external stops, while the variable air cushions manage end-of-stroke deceleration.
Airtac SAIJ125 Adjustable Cylinder SAIJ125X425-20S Technical Specifications
| Model | Airtac SAIJ125 Adjustable Cylinder SAIJ125X425-20S |
|---|---|
| Series | SAI ISO 15552 profile cylinder |
| Bore size | Ø125 mm |
| Stroke | 425 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.
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 | |
Actual usable force is lower than theoretical due to friction and back-pressure. Size with a safety margin.
Model Code: Airtac SAIJ125 Adjustable Cylinder SAIJ125X425-20S
| SAI | ISO 15552 profile-barrel cylinder series. |
|---|---|
| 125 | Bore size in mm. |
| ×425 | 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.
Where the Airtac SAIJ125 Adjustable Cylinder SAIJ125X425-20S Is Used
Heavy-Duty Press Tuning
Dial in the exact 405-425 mm end-stop during press commissioning to accommodate different material thicknesses without changing the cylinder.
Product Changeover Stops
Adjust the retract position on the fly for varying package sizes on a packaging line, using the 20 mm trim range to set precise indexing.
Large Assembly Positioning
Leverage the 6136 N push force to move heavy pallets into place, relying on the rear screw to fine-tune the final resting position.
Is the Airtac SAIJ125 Adjustable Cylinder SAIJ125X425-20S the Right Cylinder?
Choose this 125 mm bore when a smaller 100 mm cylinder (providing 3927 N at 0.5 MPa) lacks the necessary thrust, but a larger 160 mm bore is excessive. The 20 mm adjustment range is ideal for dialing in exact end stops during machine setup or product changeovers, avoiding the need to physically swap a fixed-stroke SAI cylinder. Because the nominal stroke is 425 mm, an external guide should be used to support the load and mitigate side-load stress on the M27x2 rod.
For a true ISO 15552 replacement match, verify the 125 mm bore, 425 mm stroke, 20 mm adjustment, PT ports, and the -S magnet option. The rear adjuster acts only as a travel stop and does not hold the load without live air; for load-holding requirements, consider an AirTAC SAIL or BSAI cylinder. Mounting options are limited to Basic, FA, LB, TC, FTC, TCM1, and TCM2.
Quick checklist
- ✓ Required force at your working pressure
- ✓ Stroke and mounting space
- ✓ Port/thread type (PT/NPT/G)
- ✓ Magnet (-S) for sensors?
- ✓ Side load — consider a guided cylinder
Installation & Maintenance Notes
- check Use clean air filtered to 40µm or finer.
- check Keep within 0.15 – 1.0 MPa operating pressure.
- check Avoid side load on the piston rod.
- check Adjust end cushion screws for smooth stops.
- check Use correct mounting accessory (FA/FB/CA/CB/LB/TC).
- check Installation by qualified personnel per AirTAC docs.
Airtac SAIJ125 Adjustable Cylinder SAIJ125X425-20S FAQ
At 0.5 MPa operating pressure, this 125 mm bore cylinder provides 6136 N of push force and 5734 N of pull force. It can reach a maximum push force of 11045 N at 0.9 MPa.
The rear adjuster screw allows you to shorten the effective travel from the 425 mm nominal stroke down to 405 mm. This stopper fine-tunes the end position but does not lock the load without continuous air pressure.
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