Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X70-40B
The AirTAC Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X70-40B is a genuine double acting, adjustable stroke ISO 21287 compact air cylinder with a Ø20mm bore and 70mm 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
- Stroke70 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 ACEJ20X70-40B
The ACEJ20X70-40B is a double acting ISO 21287 compact cylinder with an adjustable extend stroke: an external stop screw trims the 70 mm stroke by up to 40 mm, giving a usable range of 30-70 mm without changing the cylinder. At 0.5 MPa the 20 mm bore delivers 157.1 N push and 117.8 N pull, rising to 219.9 N push at 0.7 MPa, with a theoretical maximum of 32 kgf at 1.0 MPa.
The short ISO 21287 body saves about 50% of the mounting length of an ISO 15552 profile cylinder, so it slots into narrow jigs and guarding where a full-length body will not fit. The male rod thread (B code) suits external rod accessories, and the hard-anodized aluminium body with an S45C hard-chrome plated 10 mm rod stands up to continuous cycling. As a rule of thumb, plan for roughly 94 N of real work at 0.5 MPa, which lifts about 8 kg vertically - or about 4 kg with a 2:1 margin for a real part weight.
Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X70-40B Technical Specifications
| Model | Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X70-40B |
|---|---|
| Series | ACEJ compact cylinder |
| Standard | ISO 21287 |
| Bore size | Ø20 mm |
| Stroke | 70 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 ACEJ20X70-40B
| ACEJ | ISO 21287 compact cylinder (adjustable-stroke). |
|---|---|
| 20 | Bore size in mm. |
| ×70 | Stroke length in mm. |
| -40 | 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 ACEJ20X70-40B Is Used
Fixture clamping on CNC fixtures
The 30-70 mm adjustable window lets a machinist dial the clamp stroke to the fixture, with 157.1 N push at 0.5 MPa enough for light workholding on aluminium parts.
Small-parts ejection on assembly stations
Male rod thread takes a knuckle or tool tip to push components off a nest; the short body fits inside tight machine guarding.
Lab and test-rig actuation
Speed range 30-500 mm/s and M5x0.8 ports suit compact test benches needing repeatable 30-70 mm strokes on filtered air.
Is the Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X70-40B the Right Cylinder?
Size both ways before committing: the 16 mm bore gives 100.5 N push at 0.5 MPa if your load is lighter, while the 25 mm bore reaches 245.4 N push at 0.5 MPa for heavier clamping. If you need to hold position mid-stroke or against air loss, add an external stop or valve - the stop screw is an end stop only, not a lock. Mount with FA flange or LB foot brackets, and if position feedback is needed later, order the -S variant so CMSE / DMSE switches can be used; this model has no magnet fitted.
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 ACEJ20X70-40B FAQ
At 0.5 MPa: 157.1 N push and 117.8 N pull. At 0.7 MPa: 219.9 N push and 164.9 N pull. Theoretical maximum is 32 kgf at 1.0 MPa. 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, on air filtered to 40 um. The extend stroke is adjustable from 70 mm down to 30 mm via the stop screw.
An external stop screw shortens the extend stroke by up to 40 mm within the ordered window, so the rod stops anywhere from 30 to 70 mm; it is a mechanical end stop, not a mid-stroke lock. The body carries fixed TPU bumpers at both ends and mounts via FA flange or LB foot brackets. This model has no magnet, so CMSE / DMSE switches require ordering the -S code with the optional magnet.
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