
The AirTAC ACEJ12 Adjustable Compact Cylinder ACEJ12X40-20 is a genuine double acting, double rod, adjustable stroke ISO 21287 compact air cylinder with a Ø12mm bore and 40mm 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 ACEJ12X40-20 is a double acting ISO 21287 compact cylinder with an adjustable extend stroke. The external stop screw trims the 40 mm stroke by up to 20 mm on site, giving a usable extend range of 20-40 mm without changing the cylinder.
The short ISO 21287 body saves about 50% of the mounting length of an ISO 15552 profile cylinder, so it slots into slim fixtures, small gantries and guarded cells. The hard-anodized aluminium body carries an S45C hard-chrome plated rod, fixed TPU bumpers sit at both ends, and the rod end is female M3x0.5 with a PT port thread.
| Model | Airtac ACEJ12 Adjustable Compact Cylinder ACEJ12X40-20 |
|---|---|
| Series | ACEJ compact cylinder |
| Standard | ISO 21287 |
| Bore size | Ø12 mm |
| Stroke | 40 mm |
| Acting type | Double acting, double rod, 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 | Force (both ways) |
|---|---|
| 0.5 MPa | 42 N |
| 0.7 MPa | 59 N |
| Max (@1.0 MPa) | 9 kgf |
ACEJ is double-rod: the rear rod that carries the stroke adjuster exits the rear cover, so both piston faces lose rod area. The rod-side (annular) area is used for both directions (conservative).
| ACEJ | ISO 21287 compact cylinder (adjustable-stroke). |
|---|---|
| 12 | Bore size in mm. |
| ×40 | 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 (double rod, 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.
With the body about 50% shorter than an ISO 15552 profile cylinder, the ACEJ12X40-20 actuates small sliding guards and latches where a full-length cylinder will not fit.
The stop screw sets any extend stroke from 20 to 40 mm, ideal for repeatable light pressing or sample positioning in benchtop test stations running 0.15-1.0 MPa (22-145 psi) air.
Remember the stop screw only shortens the extend stroke and is not a mid-stroke lock: on air loss the piston drifts, so add an external stop if position must be held. FA flange or LB foot mounts bolt to the ISO 21287 face, and if you later need position sensing, order the -S variant, since this model has no magnet and no CMSE / DMSE switch can be fitted.
Quick checklist
Push is 56.5 N and pull 42.4 N at 0.5 MPa; at 0.7 MPa push reaches 79.2 N, and the theoretical maximum is 11.5 kgf at 1.0 MPa. It is double acting with an adjustable extend stroke (20 mm window, usable 20-40 mm), speed 30-500 mm/s, M5x0.8 port, female M3x0.5 rod thread, fixed TPU bumpers at both ends, and operating pressure 0.15-1.0 MPa (22-145 psi) with 1.5 MPa (215 psi) proof pressure.
The ISO 21287 short body saves about 50% of the mounting length of an ISO 15552 profile cylinder, and FA flange or LB foot mounts bolt straight to its face. Position sensing requires the optional -S magnet code: this model ships without a magnet, so CMSE / DMSE switches cannot be mounted unless you order the -S variant.
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