This model is discontinued
AirTAC has phased out the ACP series. You can still order this code here: we ship the current replacement ACEJ12X125-40B, the same code under the new prefix. The ACE replacement is a current-production ISO 21287 compact cylinder in the same bore, stroke and force class, with a matching short body and the same mounting-accessory family, so it fits the same envelope. Confirm mounting-interface dimensions against the ACE datasheet before ordering.
Airtac ACPJ Adjustable Compact Cylinder ACPJ12X125-40B
The AirTAC ACPJ Adjustable Compact Cylinder ACPJ12X125-40B is a double acting, double rod, adjustable stroke DIN-standard tight/compact air cylinder with a Ø12mm bore and 125mm stroke, M5×0.8 air ports and a hard-anodized aluminium body. This model is discontinued — the current-production replacement is the ACEJ12X125-40B (ISO 21287 ACE), in the same bore, stroke and force class.
- BoreØ12 mm
- Stroke125 mm
- Port sizeM5×0.8
- Acting typeDouble acting, double rod, adjustable stroke
- Rod threadM3×0.5
- StatusDiscontinued → ACEJ12X125-40B
- No minimum order. A single piece can be ordered.
- Ready in 3–5 business days. That is the time we take to process the order and hand it to the carrier. Transit time after that depends on the destination.
About the Airtac ACPJ Adjustable Compact Cylinder ACPJ12X125-40B
This compact cylinder is double acting: air both extends and retracts the 6 mm rod. The -40 code adds a 40 mm adjustment window, so an external stop screw trims the 125 mm extend stroke down to 85 mm on site. The 12 mm bore delivers 56.5 N push and 42.4 N pull at 0.5 MPa (79.2 N / 59.4 N at 0.7 MPa, 11.5 kgf theoretical maximum at 1.0 MPa). The 125 mm stroke exceeds the 50 mm standard limit for this bore, so it is a made-to-order build. Note this model is discontinued; the current-production replacement is ACEJ12X125.
The short ISO 21287-class body saves roughly 50% of the mounting length of an ISO 15552 profile cylinder, which is why it suits slim fixtures, test rigs and small gantries. As a rule of thumb, plan on about 34 N of usable push at 0.5 MPa, which lifts roughly 2.9 kg vertically with a 2:1 margin. A fixed TPU bumper sits at both ends, the hard-anodized aluminium body carries an S45C hard-chrome rod, and the B code gives a male rod thread with PT ports. No magnet is fitted, so position switches cannot be mounted unless you order the optional -S version for CMSE / DMSE switches.
Airtac ACPJ Adjustable Compact Cylinder ACPJ12X125-40B Technical Specifications
| Model | Airtac ACPJ Adjustable Compact Cylinder ACPJ12X125-40B |
|---|---|
| Series | ACPJ DIN compact cylinder (discontinued) |
| Replacement | ACEJ12X125-40B |
| Bore size | Ø12 mm |
| Stroke | 125 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 bumper (both ends) |
| Max standard stroke | Up to 50 mm |
Specifications follow the official AirTAC ACP datasheet (now discontinued). The ACEJ12X125-40B (ISO 21287) carries the same bore/stroke/force class; confirm mounting-interface dimensions against the ACE datasheet before installation. Rod type: female thread (blank) or male thread (B). Thread options: PT (blank) / G.
Theoretical Output Force (Ø12mm)
| Pressure | Force (both ways) |
|---|---|
| 0.5 MPa | 42 N |
| 0.7 MPa | 59 N |
| Max (@1.0 MPa) | 9 kgf |
ACPJ 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).
Model Code: Airtac ACPJ Adjustable Compact Cylinder ACPJ12X125-40B
| ACPJ | DIN compact cylinder (adjustable-stroke, discontinued). |
|---|---|
| 12 | Bore size in mm. |
| ×125 | Stroke length in mm. |
| -40 | Adjustable stroke window (mm the extend stroke can be shortened on site). |
| S | Optional built-in magnet for sensor position sensing (omit for no magnet). |
| B | Rod type: B = male thread; blank = female thread. |
Replacement mapping (swap P for E): ACP→ACE, ASP→ASE, ATP→ATE, ACPD→ACED, ACPJ→ACEJ. ACP-family: ACP (double acting), ASP / ATP (single acting push / pull), ACPD (double rod), ACPJ (double rod, adjustable stroke).
Where the Airtac ACPJ Adjustable Compact Cylinder ACPJ12X125-40B Is Used
Benchtop test station
The 85-125 mm adjustable range and about 34 N of usable push at 0.5 MPa press small sensor housings or sample clips with repeatable, tunable travel.
Compact ejection on assembly fixtures
The short body fits where an ISO 15552 profile cylinder will not, nudging finished micro-parts off a nest at 30-500 mm/s.
Gantry pick station with end detection
Order the -S version to add CMSE / DMSE switches for end-of-stroke confirmation on a 2.9 kg vertical lift class.
Replacing the Airtac ACPJ Adjustable Compact Cylinder ACPJ12X125-40B with the ACEJ12X125-40B
Size up if 56.5 N at 0.5 MPa is marginal: the 16 mm bore pushes 100.5 N and the 20 mm bore 157.1 N at the same pressure. There is no smaller bore in this family. The stop screw only shortens the extend stroke within the 40 mm window and never holds a load on air loss, so add a separate brake if the load must stay put. FA/FB flanges and LB feet bolt to the standard face, and the optional -S magnet enables CMSE / DMSE switches. Order ACEJ12X125 as the current drop-in and confirm ISO 21287 mounting dimensions before swapping.
Replacement checklist
- ✓ Current-production ACE → ACEJ12X125-40B
- ✓ Same bore / stroke / force class
- ✓ Confirm ISO 21287 mounting dimensions
- ✓ Port/thread type (PT / G)
- ✓ Add -S for magnet if you need sensors
Airtac ACPJ Adjustable Compact Cylinder ACPJ12X125-40B FAQ
At 0.5 MPa it pushes 56.5 N and pulls 42.4 N; at 0.7 MPa it pushes 79.2 N and pulls 59.4 N; theoretical maximum is 11.5 kgf at 1.0 MPa. The stop screw shortens the 125 mm extend stroke by up to 40 mm, giving a usable 85-125 mm range. The 125 mm stroke is non-standard for the 12 mm bore and is made to order.
The hard-anodized aluminium short body saves about 50% of the mounting length of an ISO 15552 profile cylinder, with a fixed TPU bumper at both ends, FA/FB flange or LB foot mounting, a male rod thread (B code) and M5x0.8 PT ports. This model is discontinued; ACEJ12X125 is the current drop-in in the same bore, stroke and force class, but confirm the ISO 21287 mounting dimensions before swapping.
Related AirTAC ACE Cylinders
Request a Quote for the ACEJ12X125-40B
Send us the quantity and destination. We confirm price, stock and lead time on the ACEJ12X125-40B replacement — usually within 7-8 hours.