The AirTAC Airtac SCJ40 Standard Cylinder SCJ40X125-30S is a genuine double-acting SINGLE-ROD air cylinder with a rear-cap ADJUSTING SCREW: the stroke end is field-adjustable within a 30 mm range without swapping the cylinder. Ø40mm bore, 125mm nominal stroke, PT1/4 ports and adjustable end cushioning.
The AirTAC SCJ40X125-30S is a double-acting, single-rod pneumatic cylinder that puts stroke-end fine-tuning directly in your hands. Its rear-cap adjusting screw provides a 30 mm adjustable range, letting you dial in the exact 125 mm maximum stroke position on the machine without swapping the cylinder or adding external hard stops. The 40 mm bore generates 628 N of push force at 0.5 MPa, driven by a 16 mm diameter piston rod, making it a capable mid-range actuator for positioning and pressing tasks.
This model includes a built-in magnet, so standard CMSG/DMSG/EMSG reed or solid-state sensors clamp directly onto the tie-rod barrel for reliable end-of-stroke sensing. The body length A is 185 mm, and the unit features a 21 mm air cushion to decelerate the piston smoothly. It uses PT1/4 ports and an M12x1.25 rod thread, operating on filtered air from 0.15 to 1.0 MPa across a standard temperature range of -20 to +70 °C.
| Model | Airtac SCJ40 Standard Cylinder SCJ40X125-30S |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder |
| Bore size | Ø40 mm |
| Nominal stroke | 125 mm |
| Stroke adjustment | Up to 30 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. |
| ×125 | Nominal (maximum) stroke length in mm. |
| -30 | 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.
Fine-tune the stroke end position by up to 30 mm during initial machine setup, eliminating the need to fabricate shims or reposition external stops for perfect alignment.
Quickly adjust the cylinder's end-stop when switching between product sizes on a packaging or sorting line, reducing downtime without replacing the actuator.
Compensate for tooling wear or material thickness variations over time by slightly advancing the stroke end, maintaining consistent process quality in clamping or pressing operations.
Choose the SCJ40 when your application needs around 628 N of push force at standard plant pressure and the flexibility to adjust the stroke end by up to 30 mm during commissioning or changeovers. If you need more force, stepping up to the SCJ50 provides 982 N of push at the same 0.5 MPa. For applications requiring a fixed, non-adjustable stroke, the standard SC series offers a simpler, more cost-effective solution. This SCJ40X125-30S is a direct replacement for an identical AirTAC model with the same bore, 125 mm nominal stroke, 30 mm adjust range, PT ports, basic mounting, and magnet.
Adjustable-stroke checklist
At 0.5 MPa, the cylinder delivers 628 N of push force and 528 N of pull force (the difference is due to the single 16 mm rod). At the maximum operating pressure of 0.9 MPa, the push force reaches 1130 N.
A screw in the rear end-cap limits how far the piston can retract. By turning this screw, you can shorten the stroke end by up to 30 mm from the nominal 125 mm maximum. It adjusts the stroke end position only; it does not change the cylinder's force or speed.
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