The AirTAC Airtac SCJ40 Standard Cylinder SCJ40X30-20 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. Ø40mm bore, 30mm nominal stroke, PT1/4 ports and adjustable end cushioning.
The SCJ40X30-20 brings field-adjustable stroke control to the 40 mm bore class, delivering 628 N of push force at 0.5 MPa (1130 N at 0.9 MPa). Its rear-cap adjusting screw provides up to 20 mm of stroke-end reduction, letting you dial in the exact piston stop position without swapping the cylinder or adding external hard stops. The 16 mm diameter piston rod and PT1/4 port thread handle typical industrial air supplies, while the 21 mm air cushion quietly decelerates the piston at each end of travel.
This double-acting, single-rod cylinder uses a tie-rod construction and is built for filtered air service from 0.15 to 1.0 MPa. The adjustable stroke feature is purely mechanical—it sets the stroke end, not the force or speed—making it ideal for commissioning trials, format changeovers, and taking up mechanical wear over time. The body length A(SCJ) is 185 mm, slightly longer than a fixed-stroke SC of the same bore to accommodate the adjusting mechanism.
| Model | Airtac SCJ40 Standard Cylinder SCJ40X30-20 |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder |
| Bore size | Ø40 mm |
| Nominal stroke | 30 mm |
| Stroke adjustment | Up to 20 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. |
| ×30 | 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.
Fine-tune the piston end stop during machine commissioning without fabricating new brackets. The 20 mm adjustment range lets technicians quickly dial in the exact stroke needed for sensor alignment or part pickup.
Adjust the ejector stroke on a packaging line to handle different box sizes. The 628 N push force easily ejects cartons or trays, and the stroke can be shortened to prevent crushing lighter products.
Take up mechanical play in a clamping or pressing fixture over time. As tooling wears, simply turn the rear adjusting screw to restore the original clamp position without disassembling the actuator.
Choose the SCJ40X30-20 when you need to fine-tune the stroke end position by up to 20 mm during setup or production. If 628 N of push force at 0.5 MPa is marginal, stepping up to a 50 mm bore SCJ50 delivers 982 N at the same pressure. For applications where the stroke is permanently fixed and never needs field adjustment, the standard SC40 series offers a simpler, more compact fixed-stroke alternative. This model is a direct replacement for another AirTAC SCJ40 adjustable-stroke cylinder with a 30 mm nominal stroke, 20 mm adjust range, PT ports, and basic mounting.
Adjustable-stroke checklist
At 0.5 MPa, the push force is 628 N and the pull force is 528 N (the difference is due to the 16 mm rod area). At the maximum operating pressure of 0.9 MPa, the push force reaches 1130 N. The theoretical maximum at 1.0 MPa is 128 kgf.
Only if you need the adjustable stroke feature. The SCJ40X30-20 has a longer body (185 mm A-length) to house the adjusting screw. It matches an SC40 in bore, port size (PT1/4), and rod thread (M12x1.25), but you must ensure the extra length fits your machine envelope.
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