Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X50-40B
The AirTAC Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X50-40B is a genuine double acting, adjustable stroke ISO 21287 compact air cylinder with a Ø20mm bore and 50mm 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
- Stroke50 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 ACEJ20X50-40B
The ACEJ20X50-40B is a double acting ISO 21287 compact cylinder with an adjustable extend stroke: an external stop screw trims the 50 mm stroke down by up to 40 mm, giving a usable range of 10-50 mm without swapping the cylinder. At 0.5 MPa it pushes with 157.1 N and pulls with 117.8 N, rising to 219.9 N on the extend stroke at 0.7 MPa. The male rod thread (B code) on the 10 mm rod bolts straight into standard tooling plates.
The hard-anodized aluminium body runs about 50% shorter than an ISO 15552 profile cylinder, so it slots into tight clamping fixtures and pick stations. Plan on roughly 94 N (about 9.6 kgf) of real work at 0.5 MPa rather than the full 157.1 N rating, which keeps the actuator inside a comfortable margin. A fixed TPU bumper at each end absorbs end-of-stroke shock, and the optional -S magnet code enables CMSE / DMSE switches - without -S there is no magnet fitted.
Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X50-40B Technical Specifications
| Model | Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X50-40B |
|---|---|
| Series | ACEJ compact cylinder |
| Standard | ISO 21287 |
| Bore size | Ø20 mm |
| Stroke | 50 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 ACEJ20X50-40B
| ACEJ | ISO 21287 compact cylinder (adjustable-stroke). |
|---|---|
| 20 | Bore size in mm. |
| ×50 | 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 ACEJ20X50-40B Is Used
Clamp fixture on a CNC jig
The 10-50 mm trim range lets one cylinder serve several part heights on a milling jig, with 157.1 N of push holding aluminium blanks against a stop.
Small-part ejection from a press die
A short 10-20 mm effective stroke punches finished bushings off the die face, and the compact body fits where a full-length profile cylinder cannot.
Gated indexing on an assembly conveyor
With the optional -S magnet and a CMSE switch, the 50 mm stroke confirms gate-open position between pallet stops at 30-500 mm/s.
Is the Airtac ACEJ12 Adjustable Compact Cylinder ACEJ20X50-40B the Right Cylinder?
For this 20 mm bore, compare downward to the 16 mm size (100.5 N push at 0.5 MPa) for lighter eject tasks, or upward to the 25 mm bore (245.4 N push) if your fixture grows. Note the adjuster is a mechanical end stop only - on air loss the piston drifts, so it is not a mid-stroke lock for holding a load. Mounting: FA flange or LB foot plus I/Y rod knuckles fit the ISO 21287 face; order the -S code if you need position sensing, since this unit ships without a magnet.
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 ACEJ20X50-40B FAQ
At 0.5 MPa it pushes 157.1 N and pulls 117.8 N; at 0.7 MPa those rise to 219.9 N and 164.9 N, with a theoretical maximum of 32 kgf at 1.0 MPa. The -40 code is a 40 mm adjustment window: an external stop screw shortens the 50 mm extend stroke on site, so the effective range is 10-50 mm. It cannot lengthen the stroke past 50 mm, and the stop is not a load-holding brake.
The ISO 21287 short body saves about 50% of the mounting length of an ISO 15552 profile cylinder, with a fixed TPU bumper at both ends and an M5x0.8 port. FA flange, LB foot and I/Y rod knuckles bolt to the standard face, and the rod end is male thread (B code). Position sensing needs the optional -S magnet ordered with the cylinder - this model has no magnet fitted, so CMSE / DMSE switches only work on the -S version.
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