
The AirTAC Airtac ACEJ12 Adjustable Compact Cylinder ACEJ12X25-20S is a genuine double acting, adjustable stroke ISO 21287 compact air cylinder with a Ø12mm bore and 25mm stroke, M5×0.8 air ports and a hard-anodized aluminium body. Its short compact envelope saves about 50% of the mounting length of an ISO 15552 profile cylinder.
The ACEJ12X25-20S is a double acting ISO 21287 compact cylinder with an adjustable extend stroke: a 12 mm bore, a 25 mm stroke and a 20 mm adjustment window, so the stop screw lets you trim the extend stroke anywhere from 5 to 25 mm on site. At 0.5 MPa it pushes 56.5 N and pulls 42.4 N, rising to 79.2 N push at 0.7 MPa, with a theoretical maximum of 11.5 kgf at 1.0 MPa. The short body saves about 50% of the mounting length of an ISO 15552 profile cylinder, which is why it slots into tight fixture plates and small guarding frames. As an -S model the magnet is fitted, so CMSE / DMSE reed or solid-state switches can be mounted in the body slots for end-of-stroke sensing.
For sizing, plan on roughly 33.9 N (about 0.6 of the push force) of usable work at 0.5 MPa, which corresponds to lifting about 2.9 kg vertically with a 2:1 margin - enough for small covers, sensors carriers or light clamping fingers. The hard-anodized aluminium body carries a hard-chrome plated S45C rod with a female M3x0.5 thread, a fixed TPU bumper at each end absorbs end-of-stroke shock, and the air supply runs at 0.15-1.0 MPa (22-145 psi) with speeds of 30-500 mm/s.
| Model | Airtac ACEJ12 Adjustable Compact Cylinder ACEJ12X25-20S |
|---|---|
| Series | ACEJ compact cylinder |
| Standard | ISO 21287 |
| Bore size | Ø12 mm |
| Stroke | 25 mm |
| Acting type | Double acting, adjustable stroke |
| Port size | M5×0.8 |
| Rod thread | M3×0.5 |
| 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 – 500 mm/s |
| Cushion | Fixed TPU bumper (both ends) |
| Max standard stroke | Up to 50 mm |
Specifications follow the official AirTAC ACE-series (ISO 21287) datasheet. Body: hard-anodized aluminium alloy; piston rod: S45C carbon steel with hard-chrome plating. Rod type: female thread (blank) or male thread (B). Thread options: PT (blank) / G. A built-in magnet is OPTIONAL — add the -S code to fit CMSE / DMSE position sensors.
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 57 N | 42 N |
| 0.7 MPa | 79 N | 59 N |
| Max (@1.0 MPa) | 12 kgf | |
Actual usable force is lower than theoretical due to friction and back-pressure. Size with a safety margin.
| ACEJ | ISO 21287 compact cylinder (adjustable-stroke). |
|---|---|
| 12 | Bore size in mm. |
| ×25 | Stroke length in mm. |
| -20 | Adjustable stroke window (mm the extend stroke can be shortened on site). |
| S | Optional built-in magnet for CMSE / DMSE sensors (omit for no magnet). |
| B | Rod type: B = male thread; blank = female thread. |
ACE-family variants: ACE (double acting), ASE / ATE (single acting push / pull), ACED (double rod), ACEJ (adjustable stroke), TACE / TACED (non-rotating twin-guide yoke). Mounting accessories: FA / FB flange, LB foot, CA / CB clevis, CR, SDB pivot, FTC; plus I and Y knuckles. Thread PT (blank) / G.
A 56.5 N push at 0.5 MPa is right for holding small aluminium brackets during a drilling or marking pass, with the 5-25 mm trimmed stroke matching shallow part pockets.
The fitted -S magnet lets a CMSE switch signal full extension, so an electronics test bench can verify the part was pushed home into its nest before the probe cycle starts.
The short ISO 21287 body fits inside compact analysis enclosures, and the adjustable stroke lets a technician dial the pusher travel to slide vials between stations.
At 56.5 N push at 0.5 MPa this 12 mm bore suits light clamping and positioning; step down is not available (12 mm is the smallest ACEJ bore), while a 16 mm bore gives 100.5 N push at 0.5 MPa if your load grows. Remember the stop screw only shortens the extend stroke within the 20 mm window - it is a mechanical end stop, not a mid-stroke lock, so the rod will drift if air is lost. FA flange or LB foot mounts bolt to the ISO 21287 face, and the fitted -S magnet pairs with CMSE / DMSE switches.
Quick checklist
At 0.5 MPa it pushes 56.5 N and pulls 42.4 N; at 0.7 MPa it pushes 79.2 N and pulls 59.4 N; theoretical maximum is 11.5 kgf at 1.0 MPa. It is double acting with a 25 mm stroke adjustable down to 5 mm via the 20 mm window, air supply 0.15-1.0 MPa (22-145 psi), proof pressure 1.5 MPa (215 psi), speed 30-500 mm/s, temperature -20 to +70 C, M5x0.8 port and a female M3x0.5 rod thread.
The ISO 21287 short body saves about 50% of the mounting length of an ISO 15552 profile cylinder, so it fits where space is tight. FA flange and LB foot brackets bolt to the standard face, and because this is an -S model the magnet is fitted, so CMSE / DMSE reed or solid-state switches can be slid into the body slots. A fixed TPU bumper at each end absorbs end-of-stroke shock.
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