The AirTAC Airtac SCJ40 Standard Cylinder SCJ40X120-50 is a genuine double-acting SINGLE-ROD air cylinder with a rear-cap ADJUSTING SCREW: the stroke end is field-adjustable within a 50 mm range without swapping the cylinder. Ø40mm bore, 120mm nominal stroke, PT1/4 ports and adjustable end cushioning.
The SCJ40X120-50 is a 40 mm bore, double-acting, single-rod pneumatic cylinder with a field-adjustable stroke end. A rear-cap adjusting screw provides up to 50 mm of stroke shortening, allowing the effective stroke to be fine-tuned between 70 and 120 mm without removing the cylinder. At 0.5 MPa, it delivers 628 N of push force and 528 N of pull force, making it a versatile actuator for mid-force applications.
This tie-rod cylinder uses a 16 mm diameter piston rod with an M12x1.25 thread and PT1/4 ports. The body length A(SCJ) is 185 mm, and it features an adjustable air cushion of 21 mm for smooth end-of-stroke deceleration. The standard operating pressure is 0.15–1.0 MPa, with a speed range of 30–800 mm/s. It is a genuine AirTAC component built for reliable, repeatable performance.
| Model | Airtac SCJ40 Standard Cylinder SCJ40X120-50 |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder |
| Bore size | Ø40 mm |
| Nominal stroke | 120 mm |
| Stroke adjustment | Up to 50 mm (rear adjusting screw) |
| Acting type | Double acting (single rod) |
| Port size | PT1/4 |
| Rod thread | M12×1.25 |
| 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, 21 mm |
| Max stroke | Up to 1200 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 | 628 N | 528 N |
| 0.7 MPa | 880 N | — |
| Max (@1.0 MPa) | 128 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. |
|---|---|
| 40 | Bore size in mm. |
| ×120 | Nominal (maximum) stroke length in mm. |
| -50 | 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 50 mm adjust range allows technicians to dial in the exact stroke end-stop during initial machine setup, eliminating the need to swap cylinders or fabricate external hard stops for a 120 mm nominal stroke.
Ideal for packaging lines where the push distance must be altered for different product sizes. The rear screw is easily accessed to shorten the stroke from 120 mm down to 70 mm, reducing downtime between batches.
In clamping or pressing fixtures, the adjustable stroke can be gradually extended over time to compensate for tooling or pad wear, maintaining consistent contact force without reprogramming the machine controller.
Choose the SCJ40X120-50 when you need a mid-range force actuator that can be precisely tuned on the machine during commissioning or format changes. If you require more force, step up to the 50 mm bore SCJ50, which provides 982 N of push force at the same 0.5 MPa pressure. For a fixed, non-adjustable stroke, the standard SC series is a simpler, more cost-effective alternative.
A direct replacement must match the 40 mm bore, 120 mm nominal stroke, 50 mm adjust range, PT1/4 port thread, and basic mounting. If you are adding a magnet for sensors, the code would be SCJ40X120-50S. For strokes of 300 mm or more, consider an external guide or a guided cylinder to protect the 16 mm rod from side-loading and bending.
Adjustable-stroke checklist
The push force is 628 N at 0.5 MPa and 1130 N at the maximum operating pressure of 0.9 MPa. The pull force is lower due to the single-rod design, providing 528 N at 0.5 MPa. The theoretical maximum force at 1.0 MPa is 128 kgf.
Yes, provided the mounting and porting are compatible. The SCJ body is slightly longer to house the adjusting screw. You must match the 40 mm bore, PT1/4 ports, and basic mounting. The SCJ adds the ability to shorten the stroke by up to 50 mm, which the fixed SC cannot do.
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