The AirTAC Airtac SCJ40 Standard Cylinder SCJ40X120-30STC 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, 120mm nominal stroke, PT1/4 ports and adjustable end cushioning.
The SCJ40X120-30STC is a 40 mm bore double-acting, single-rod pneumatic cylinder with a field-adjustable stroke end. Its rear-cap adjusting screw provides up to 30 mm of stroke shortening, allowing engineers to fine-tune the end position during commissioning or format changeovers without replacing the cylinder. With a 16 mm diameter piston rod and PT1/4 ports, it delivers 628 N of push force at 0.5 MPa.
This model is configured with a built-in magnet (-S) for direct mounting of CMSG/DMSG/EMSG sensors, and a centre trunnion (TC) mount that ships with the TCM1 bracket, ideal for pivoting applications. The body length A(SCJ) is 185 mm, and the adjustable air cushion decelerates the piston smoothly at stroke end. As a genuine AirTAC component, it ensures reliable performance in automated machinery.
| Model | Airtac SCJ40 Standard Cylinder SCJ40X120-30STC |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder |
| Bore size | Ø40 mm |
| Nominal stroke | 120 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. |
| ×120 | 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.
The 30 mm adjustment screw lets technicians dial in the exact stroke end position during initial machine setup, compensating for small assembly tolerances without needing to swap the cylinder or add external hard stops.
On packaging or sorting lines that handle different product sizes, operators can quickly adjust the cylinder's end stop to match a new format, minimizing downtime between production runs.
In clamping or pressing fixtures, the adjustable stroke can be used to take up mechanical wear on tooling or contact surfaces over time, maintaining consistent clamping force and position without replacing parts.
Choose the SCJ40 bore when your application needs around 628 N of push force at standard plant air. If you require more force, step up to the SCJ50 which provides 982 N of push at the same pressure. For lower force requirements, the SCJ32 offers 402 N. This adjustable-stroke version is the right choice when the machine's end-stop position needs periodic tweaking; if the stroke is fixed and never changes, a standard SC cylinder is a more economical alternative.
For this 120 mm stroke, side-loading is typically not a primary concern, but always ensure the load is guided externally if any radial force is present. As a direct replacement, match this unit with another SCJ40 cylinder featuring a 120 mm nominal stroke, a 30 mm adjustment range, PT ports, a centre trunnion mount (F-SC40TC), and a magnetic piston for sensor compatibility.
Adjustable-stroke checklist
At 0.5 MPa operating pressure, this 40 mm bore cylinder generates 628 N of push force and 528 N of pull force. The pull force is lower because the 16 mm piston rod reduces the effective area on the return stroke. Maximum push force at 0.9 MPa is 1130 N.
Yes, provided the mounting style and port size match. The SCJ40X120-30STC has a centre trunnion mount and a magnetic piston. When replacing a fixed-stroke SC, ensure the 30 mm adjustment range is suitable for your application, as the SCJ body is slightly longer to accommodate the rear adjusting mechanism.
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