Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X40-20B
The AirTAC Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X40-20B is a genuine double acting, adjustable stroke ISO 21287 compact air cylinder with a Ø20mm 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.
- BoreØ20 mm
- Stroke40 mm
- Port sizeM5×0.8
- Acting typeDouble acting, adjustable stroke
- Rod threadM6×1.0
- CushionFixed TPU bumper (both ends)
About the Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X40-20B
The ACEJ20X40-20B is a double acting AirTAC compact cylinder built to ISO 21287, with a 20 mm bore, a 40 mm stroke and a male rod thread from the B code. An external stop screw trims the extend stroke anywhere within the ordered 20 mm window, so the working range is 20-40 mm; the trim shortens the stroke only and never extends it past 40 mm. At 0.5 MPa it pushes 157.1 N and pulls 117.8 N, which suits light clamping, indexing and small part ejection on compact automation.
The short ISO 21287 body saves about 50% of the mounting length of an ISO 15552 profile cylinder, so it slots into tight fixtures, guarding and gantries. The hard-anodized aluminium body carries a hard-chrome plated S45C rod, and a fixed TPU bumper at each end absorbs end-of-stroke energy. For vertical work, treat roughly 0.6 of the push force as usable, about 94 N, which lifts roughly 9 kg with margin. This version has no magnet; order the optional -S code if you later want CMSE or DMSE switch sensing.
Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X40-20B Technical Specifications
| Model | Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X40-20B |
|---|---|
| Series | ACEJ compact cylinder |
| Standard | ISO 21287 |
| Bore size | Ø20 mm |
| Stroke | 40 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.
Theoretical Output Force (Ø20mm)
| 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.
Model Code: Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X40-20B
| ACEJ | ISO 21287 compact cylinder (adjustable-stroke). |
|---|---|
| 20 | 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 (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.
Where the Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X40-20B Is Used
Small-part press fitting
Pressing dowel pins or bushings into plastic housings on an electronics assembly bench, where the 157.1 N push at 0.5 MPa is enough and the 20-40 mm trim lets one cylinder serve several housing heights.
Adjustable stop on a pick station
Acting as a height-settable end stop for cartons or trays on a packaging line, with the stop screw set per SKU instead of swapping hardware.
Light gate clamping in jigs
Holding thin aluminium extrusions against a jig fence during drilling, using the male rod thread to bolt a custom clamp pad directly to the rod.
Is the Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X40-20B the Right Cylinder?
Check the load both ways: at 0.5 MPa this 20 mm bore gives 157.1 N push and 117.8 N pull, while the smaller 16 mm bore manages only 100.5 N push and the larger 25 mm bore reaches 245.4 N push. If your pull-side load dominates, step up, because the rod side loses area. The stop screw is a mechanical end stop for the extend stroke, not a mid-stroke lock, so the piston can drift if air is lost. Mount with FA flange or LB foot on the ISO 21287 face, add I or Y rod knuckles for side misalignment, and specify the -S code if CMSE or DMSE switches are planned. Speed range is 30-500 mm/s at 0.15-1.0 MPa (22-145 psi).
Quick checklist
- ✓ Required force at your working pressure
- ✓ Short stroke fits the compact body
- ✓ Port/thread type (PT / G)
- ✓ Add -S if you need the magnet for sensors
- ✓ Rod type (female / male B) & mount (FA/LB/CA)
Installation & Maintenance Notes
- check Use clean air filtered to 40µm or finer.
- check Keep within 0.15 – 1.0 MPa operating pressure.
- check Compact body: keep the stroke short and avoid side load on the rod.
- check Do not dismantle the threaded front/back covers.
- check Keep speed within the rated range; the TPU bumper absorbs stroke-end energy.
- check Installation by qualified personnel per AirTAC docs.
Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X40-20B FAQ
At 0.5 MPa it pushes 157.1 N and pulls 117.8 N; at 0.7 MPa push rises to 219.9 N and pull to 164.9 N; the theoretical maximum is 32 kgf at 1.0 MPa. Operating pressure is 0.15-1.0 MPa (22-145 psi) with a 1.5 MPa (215 psi) proof pressure, air filtered to 40 um, speed 30-500 mm/s and temperature -20 to +70 C. The extend stroke is trimmed by an external stop screw anywhere in the ordered 20 mm window, giving 20-40 mm of usable travel.
The -20 code sets a 20 mm adjustment window: a stop screw at the head end shortens the 40 mm extend stroke on site, so the effective range is 20-40 mm; it cannot lengthen the stroke beyond 40 mm. The B code gives a male rod thread on the 10 mm rod, and the port is M5x0.8. The body is a compact ISO 21287 build about 50% shorter in mounting length than an ISO 15552 profile cylinder, with fixed TPU bumpers at both ends that only decelerate at the ends of travel. Sensing needs the optional -S magnet, ordered at purchase, to work with CMSE or DMSE switches; this model without S carries no magnet.
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