
The AirTAC Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X55-20 is a genuine double acting, adjustable stroke ISO 21287 compact air cylinder with a Ø20mm bore and 55mm 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.
A double acting compact cylinder built to ISO 21287, the ACEJ20X55-20 pairs a 20 mm bore with a 55 mm stroke and an external stop screw that trims the extend stroke by up to 20 mm on site, giving a usable 35-55 mm range. At 0.5 MPa it pushes 157.1 N and pulls 117.8 N; at 0.7 MPa those figures rise to 219.9 N and 164.9 N, with a theoretical 32 kgf at 1.0 MPa. The short body saves about 50% of the mounting length of an ISO 15552 profile cylinder, so it slots into tight fixtures a full-length body cannot reach.
In practice, plan on roughly 94 N of real work at 0.5 MPa, which lifts about 8 kg vertically with a 2:1 margin. The hard-anodized aluminium body carries a roller-burnished bore, the S45C rod is hard-chrome plated, and fixed TPU bumpers absorb end-of-stroke energy. Air supply is 0.15-1.0 MPa (22-145 psi), speed 30-500 mm/s, and the port is M5x0.8. Note that no magnet is fitted on this code; the optional -S version enables CMSE / DMSE switch sensing.
| Model | Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X55-20 |
|---|---|
| Series | ACEJ compact cylinder |
| Standard | ISO 21287 |
| Bore size | Ø20 mm |
| Stroke | 55 mm |
| Acting type | Double acting, adjustable stroke |
| Port size | M5×0.8 |
| Rod thread | M6×1.0 |
| 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 100 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 | 157 N | 118 N |
| 0.7 MPa | 220 N | 165 N |
| Max (@1.0 MPa) | 32 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). |
|---|---|
| 20 | Bore size in mm. |
| ×55 | 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.
The 35-55 mm adjustable throw lets a fixture builder dial in the exact eject distance for stamped terminals or connector housings, with 157.1 N of push at 0.5 MPa clearing parts reliably.
About 8 kg of vertical lift capacity with a 2:1 margin seats vials or caps in diagnostic analysers, and the short ISO 21287 body fits inside compact instrument enclosures.
The stop screw trims the extend stroke so the pad contacts the flap at a repeatable height, and the fixed TPU bumper quiets each cycle at speeds up to 500 mm/s.
For light clamping and positioning in the 100-160 N class at 0.5 MPa, the 20 mm bore is the right size: a 16 mm bore delivers only 100.5 N push, while a 25 mm bore jumps to 245.4 N, so step up only if your load exceeds about 94 N of working force. The 55 mm stroke sits well inside the 100 mm standard limit for this bore. The stop screw is a mechanical end stop only - on air loss the piston drifts, so do not rely on it to hold a load mid-stroke. FA flange or LB foot mounts bolt to the ISO 21287 face, and if you need position feedback, order the -S code to add the magnet for CMSE / DMSE switches.
Quick checklist
This 20 mm bore model pushes 157.1 N and pulls 117.8 N at 0.5 MPa; at 0.7 MPa it reaches 219.9 N push and 164.9 N pull, with a theoretical maximum of 32 kgf at 1.0 MPa. It is double acting with an adjustable extend stroke: the -20 window lets the stop screw trim the 55 mm stroke down to 35 mm. Operating pressure is 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, port M5x0.8, female rod thread M6x1.0, PT fluid ports.
The ISO 21287 short body saves about 50% of the mounting length of an ISO 15552 profile cylinder, which is why it fits shallow jigs and guarded gantries. Fixed TPU bumpers at both ends absorb end-of-stroke energy, and FA flange or LB foot mounts bolt straight to the standard face. Sensing is not included on this code: order the optional -S magnet version to run CMSE or DMSE switches along the body slots.
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