The AirTAC Airtac SCJ80 Standard Cylinder SCJ80X125-20S 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. Ø80mm bore, 125mm nominal stroke, PT3/8 ports and adjustable end cushioning.
The SCJ80X125-20S is an 80 mm bore, double-acting single-rod pneumatic cylinder with a field-adjustable stroke. Its rear-cap adjusting screw provides up to 20 mm of stroke-end adjustment from the 125 mm nominal maximum, letting you fine-tune the end position during commissioning or changeovers without replacing the unit. The built-in magnet allows direct mounting of CMSG/DMSG/EMSG sensors for reliable end-of-stroke detection.
With a 25 mm diameter piston rod and PT3/8 ports, this tie-rod cylinder delivers a substantial 2513 N of push force at 0.5 MPa and up to 4523 N at the maximum operating pressure of 0.9 MPa. The adjustable air cushion, with a 28 mm cushion length, decelerates the piston smoothly at both ends, protecting your tooling across a speed range of 30-800 mm/s.
| Model | Airtac SCJ80 Standard Cylinder SCJ80X125-20S |
|---|---|
| Series | SCJ adjustable-stroke tie-rod cylinder |
| Bore size | Ø80 mm |
| Nominal stroke | 125 mm |
| Stroke adjustment | Up to 20 mm (rear adjusting screw) |
| Acting type | Double acting (single rod) |
| Port size | PT3/8 |
| Rod thread | M20×1.5 |
| 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 | 2513 N | 2268 N |
| 0.7 MPa | 3519 N | — |
| Max (@1.0 MPa) | 513 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. |
|---|---|
| 80 | 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 technicians to quickly dial in the exact stroke end position during initial machine setup, eliminating the need to fabricate shims or reposition external hard stops for a perfect fit.
On packaging lines, operators can adjust the cylinder's stroke to accommodate different product sizes or box formats. The magnetic piston enables sensor-based verification of the new end position for each format.
In clamping or pressing applications, the adjustable stroke can be used to take up mechanical wear on tooling or workpieces over time, maintaining consistent contact force without reprogramming the machine controller.
Choose this 80 mm bore model when you need a robust force of 2513 N push at 0.5 MPa. If your application requires less force, the 63 mm bore SCJ63 series provides 1559 N push at the same pressure, offering a more compact and economical solution. For higher force demands, stepping up to the 100 mm bore SCJ100 delivers 3927 N push at 0.5 MPa.
This SCJ model is ideal when the stroke end position needs frequent or precise on-machine tuning, unlike a fixed-stroke SC cylinder. For a drop-in replacement, match an AirTAC SCJ80 with a 125 mm nominal stroke, a 20 mm adjustment range, PT ports, and a magnet-equipped barrel. The 125 mm stroke is well within standard limits, but always ensure the rod is guided externally if significant side loads are present to prevent bending and seal wear.
Adjustable-stroke checklist
The push force is 2513 N at 0.5 MPa and 4523 N at 0.9 MPa. The pull force on the return stroke is lower due to the 25 mm rod area, providing 2268 N at 0.5 MPa. These forces are identical to a fixed-stroke SC80 cylinder of the same bore.
No. Like all standard pneumatic cylinders, the SCJ80X125-20S will not hold its position if air pressure is lost or the valve is centered. The adjustable screw only sets the stroke end, not a mechanical lock. You must add an external rod brake, pilot-operated check valve, or a mechanical lock to hold a load safely without live pressure.
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