Airtac SAIJ125 Adjustable Cylinder SAIJ125AX250-40S
The AirTAC Airtac SAIJ125 Adjustable Cylinder SAIJ125AX250-40S is a genuine double-acting ISO 15552 profile-barrel air cylinder with a Ø125mm bore and 250mm 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
- Stroke250 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2
- CushionAdjustable, 40 mm
About the Airtac SAIJ125 Adjustable Cylinder SAIJ125AX250-40S
The AirTAC SAIJ125X250-40-S is a double-acting ISO 15552 profile cylinder equipped with a rear stroke adjuster, enabling you to fine-tune the travel end position without swapping out the unit. By turning the integrated stopper, you achieve a usable travel window of 210 to 250 mm, allowing precise end-position tuning during commissioning or product changeovers. This 125 mm bore generates 6136 N of push force at 0.5 MPa and up to 11045 N at 0.9 MPa, making it well-suited for heavy-duty positioning tasks.
This variant features a SUS420J2 stainless steel rod for enhanced durability against moisture and a PT tapered port thread for a robust pneumatic seal. The extruded aluminum barrel includes sensor grooves on both sides, and because this SKU includes a magnet (-S), it is fully compatible with AirTAC CMSE reed and DMSE electronic solid-state switches for precise position feedback. The rear adjuster acts purely as a mechanical stop to set deceleration and travel limits; it does not hold the load without live air pressure.
Airtac SAIJ125 Adjustable Cylinder SAIJ125AX250-40S Technical Specifications
| Model | Airtac SAIJ125 Adjustable Cylinder SAIJ125AX250-40S |
|---|---|
| Series | SAI ISO 15552 profile cylinder |
| Bore size | Ø125 mm |
| Stroke | 250 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 SAIJ125AX250-40S
| SAI | ISO 15552 profile-barrel cylinder series. |
|---|---|
| 125 | Bore size in mm. |
| ×250 | 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 SAIJ125AX250-40S Is Used
Product Changeover Adjustment
Dial in the 210-250 mm travel window on the fly to accommodate different package sizes or material lengths during line changeovers without changing the cylinder.
Heavy-Duty End Positioning
Leverage the 11045 N of push force at 0.9 MPa to move heavy pallets or fixtures, using the rear stopper to precisely set the final deceleration point.
Commissioning Stroke Tuning
Fine-tune the retract end-position during initial machine setup to avoid mechanical crashes, using the external adjuster instead of adding external stops.
Is the Airtac SAIJ125 Adjustable Cylinder SAIJ125AX250-40S the Right Cylinder?
Selecting this 125 mm bore makes sense when your application demands high thrust, such as 6136 N at 0.5 MPa, which is a significant step up from the 80 mm bore's 2513 N. If your force requirements are lower, stepping down to an 80 mm bore saves space and air consumption. The adjustable stroke is chosen over a fixed SAI cylinder when you need variable end-stops for machine setup or accommodating multiple product sizes on the same line. For strokes of 250 mm or more, ensure you use an external guide to prevent excessive side-loading on the 32 mm rod, as the adjuster only sets the travel end and provides no structural support for lateral forces.
When matching this cylinder for an ISO 15552 interchangeable replacement, verify the 125 mm bore, 250 mm nominal stroke, 40 mm adjustment range, PT port threads, and the -S magnet requirement. The SAIJ mounting set includes Basic, FA, LB, TC, FTC, TCM1, and TCM2 options, omitting FB, CA, CB, and CR. If your application requires true load-holding without live air pressure, this cylinder is not a lock; consider the AirTAC SAIL or BSAI series instead.
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 SAIJ125AX250-40S FAQ
The rear adjusting screw acts as a mechanical stopper that lets you shorten the effective stroke by up to 40 mm. This provides a usable travel window of 210 to 250 mm, allowing you to fine-tune the end position without replacing the cylinder.
At 0.5 MPa, it provides 6136 N of push force and 5734 N of pull force. At 0.9 MPa, the push force increases to 11045 N. Note that the rear adjuster only sets the travel end and does not hold the load without live air pressure.
Authorized Export Seller
Genuine AirTAC parts produced by AirTAC factory.
1-Year Warranty
Covers non-human-caused product damage.
Fast Dispatch
Standard models usually ship in 3-4 days.
Fast Reply
Most inquiries answered within 7-8 hours.
Related AirTAC SAI Cylinders
Request a Quote for Airtac SAIJ125 Adjustable Cylinder SAIJ125AX250-40S
Send us the quantity and destination. We confirm price, stock and lead time — usually within 7-8 hours.