The AirTAC Airtac SCJ63 Standard Cylinder SCJ63X125-20S is a genuine double-acting SINGLE-ROD air cylinder with a rear-cap ADJUSTING SCREW: the stroke end is field-adjustable within a 20 mm range without swapping the cylinder. Ø63mm bore, 125mm nominal stroke, PT1/4 ports and adjustable end cushioning.
The SCJ63X125-20S is a double-acting, single-rod pneumatic cylinder from AirTAC, featuring a rear-cap adjusting screw that provides a 20 mm field-adjustable stroke range. This allows precise end-position tuning without removing the cylinder, ideal for commissioning and format changeovers. The built-in magnet enables direct mounting of CMSG/DMSG/EMSG sensors for reliable position feedback.
With a 63 mm bore, it delivers a substantial 1559 N of push force at 0.5 MPa and up to 2805 N at the maximum operating pressure of 0.9 MPa. The 20 mm rod features an M16x1.5 thread, and the cylinder body length is 197 mm plus stroke. It operates with filtered air and includes an adjustable pneumatic cushion for smooth deceleration.
| Model | Airtac SCJ63 Standard Cylinder SCJ63X125-20S |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder |
| Bore size | Ø63 mm |
| Nominal stroke | 125 mm |
| Stroke adjustment | Up to 20 mm (rear adjusting screw) |
| Acting type | Double acting (single rod) |
| Port size | PT1/4 |
| Rod thread | M16×1.5 |
| 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 – 800 mm/s |
| Cushion | Adjustable, 28 mm |
| Max stroke | Up to 1500 mm |
Specifications follow the official AirTAC SCJ (adjustable-stroke) datasheet. The rear adjusting screw sets the stroke end position; force is the same as the equivalent single-rod SC bore. Confirm against the product label before installation. Thread options: PT (standard) / G.
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 1559 N | 1402 N |
| 0.7 MPa | 2182 N | — |
| Max (@1.0 MPa) | 318 kgf | |
SCJ is single-rod, so force matches the equivalent SC bore: push uses the full bore area, pull subtracts the rod area. Actual usable force is lower than theoretical due to friction and back-pressure; size with a safety margin.
| SCJ | Adjustable-stroke tie-rod cylinder series. |
|---|---|
| 63 | Bore size in mm. |
| ×125 | Nominal (maximum) stroke length in mm. |
| -20 | Adjustable-stroke range in mm (options 10/20/30/40/50/75/100). |
| -S | Optional built-in magnet for sensor position sensing. |
Related types: SC (single rod, fixed stroke), SCD (double rod), SCT (multi-position). SCJ mounting: Basic, FA, LB, TC, TCM1. Seals: TPU standard / H = Viton / N = NBR. Thread: blank = PT, G = G thread.
The 20 mm adjustment screw allows operators to dial in the exact stroke end position during machine commissioning or after maintenance, compensating for tooling wear or material thickness variations on the fly.
With the built-in magnet, this cylinder pairs with CMSG sensors for precise end-of-stroke detection in automated clamping or part-ejection stations, ensuring the 125 mm stroke is fully completed before the next cycle.
Quickly adapt the cylinder's stroke for different product sizes on a packaging or assembly line. The rear screw adjustment eliminates the need to swap cylinders or add external hard stops, slashing changeover time.
Choose the SCJ63X125-20S when you need a robust mid-bore cylinder with on-machine stroke fine-tuning and integrated magnetic sensing. If your force requirement is lower, stepping down to a 50 mm bore reduces push force to 982 N at 0.5 MPa; for higher demands, the 80 mm bore offers 2513 N. This adjustable-stroke model is the correct choice over a fixed-stroke SC when the application requires end-position variability.
For a direct replacement, match the 63 mm bore, 125 mm nominal stroke, 20 mm adjustment range, PT port thread, and the built-in magnet. This cylinder uses the basic mounting style; if a pivoting mount is needed, select a model with the TC suffix for a center trunnion. For strokes of this length, ensure the load is guided to prevent excessive side-loading on the rod and seals.
Adjustable-stroke checklist
The theoretical push force at 0.5 MPa is 1559 N, and the pull force is 1402 N. At the maximum operating pressure of 1.0 MPa, the push force reaches 2805 N. The pull force is lower due to the area of the 20 mm piston rod.
Yes, it can replace an SC cylinder of the same 63 mm bore and 125 mm nominal stroke if you need the added 20 mm adjustable stroke feature. Ensure the mounting style, port thread (PT), and magnet option (S) also match your existing setup. The SCJ body is slightly longer to accommodate the adjusting screw.
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