Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-20
The AirTAC Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-20 is a double-acting, double-rod pen-size mini cylinder whose rear rod carries a stroke adjuster. On a Ø12mm bore it gives a nominal 125mm stroke with a 20mm fine-adjustable window — settable from 105 to 125mm, so you set the end position without changing hardware.
- BoreØ12 mm
- Nominal stroke125 mm
- Adjust window20 mm
- Effective range105–125 mm
- Port sizeM5×0.8
- Acting typeDouble acting
- 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 PBJ Adjustable Pen-Type Cylinder PBJ12X125-20
The AirTAC PBJ12X125-20 is a double-acting, double-rod pen-size mini cylinder featuring a 20mm adjustable stroke window. A rear adjuster screw shortens the retract end, providing an effective stroke range of 105-125mm. You can set the exact length on the machine without changing hardware. The extend end remains fixed. The bore is 12mm, the port is M5x0.8, and the piston rod is Ø5mm.
The slim body uses a SUS304 stainless steel rod and barrel. A fixed TPU bumper at each end decelerates the last few millimeters of travel. Because the rod is only Ø5mm, you should add an external guide or linear bearing for long strokes or off-axis loads. The thin rod is designed for coaxial thrust, not side load.
Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-20 Technical Specifications
| Model | Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-20 |
|---|---|
| Series | PBJ JIS pen-size adjustable-stroke cylinder |
| Bore size | Ø12 mm |
| Rod diameter | Ø5 mm |
| Nominal stroke | 125 mm |
| Adjustable window | 20 mm (105–125 mm) |
| Adjuster thread | M5×0.8 |
| Port size | M5×0.8 |
|---|---|
| Operating pressure | 0.15 – 0.7 MPa |
| Proof pressure | 1.2 MPa |
| Temperature | -20 to +70 °C |
| Speed range | 50 – 800 mm/s |
| Cushion | Elastic bumper (both ends) |
| Max standard stroke | Up to 200 mm |
PBJ is a double-rod cylinder: the rear rod carries the stroke adjuster, which sets the stroke end within the adjustable window. Confirm the set position against the product label before installation.
Theoretical Output Force (Ø12mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 46.7 N | 46.7 N |
| 0.7 MPa (max) | 65.4 N | 65.4 N |
The rear rod passes through the rear cover, so both piston faces lose rod area: push is shown at the annular-area value (conservative), lower than a single-rod PB push of the same bore. Size with a friction margin.
Model Code: Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-20
| PBJ | JIS pen-size adjustable-stroke mini-cylinder series. |
|---|---|
| 12 | Bore size in mm. |
| ×125 | Nominal stroke length in mm. |
| -20 | Adjustable-stroke window in mm (10/20/30/40/50/75/100). |
| S | Built-in magnet for magnetic-switch position sensing (omit = no magnet). |
Fixed body — no separate back-cover code. Mounting accessories: LB, FA. Related PB-family variants: PB (fixed stroke), PBD (double rod), PBR (front-mount).
Where the Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-20 Is Used
Changeover Fixtures
Dial in the exact retract stop during product changeovers on shared machining fixtures without machining new spacers.
Trial Insertion Stops
Test different insertion depths for pins or plugs on a test rig, locking the rear nut once the optimal position is found.
Variable Lift Jigs
Lift light workpieces to varying heights in compact assembly jigs, adjusting the up-stroke on the fly for different part profiles.
Is the Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-20 the Right Cylinder?
Remember that only the retract position is adjustable here. You must re-tighten the lock nut after setting the rear screw to prevent vibration drift. Confirm your ordering essentials: 12mm bore, 125mm nominal stroke, 20mm window, no magnet, and your preferred mounting option.
This accounts for seal friction and smooth travel. The fixed TPU bumper only decelerates the final few millimeters. At higher speeds with real tooling mass, it will bottom out. You should meter-out the exhaust or fit an external shock absorber.
Quick checklist
- ✓ Need to fine-tune the end position on site
- ✓ Retract end sits within 105–125 mm
- ✓ Force at your working pressure
- ✓ Magnet (S) for sensors?
- ✓ Access to the rear adjuster screw
- ✓ Keep the load coaxial — avoid side load
Installation & Maintenance Notes
- check Use clean air filtered to 40µm or finer.
- check Keep within 0.15 – 0.7 MPa operating pressure.
- check Set the adjuster, then re-lock the check nut.
- check Double rod: the rear rod carries the stroke adjuster.
- check Keep the load coaxial; avoid side load on the thin rod.
- check Do not dismantle the front or back cover.
Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-20 FAQ
The effective stroke range is 105-125mm. The maximum operating pressure is 0.7MPa.
The rear M5x0.8 screw shortens the retract end only; the extend end is fixed. You must re-tighten the lock nut after setting to prevent vibration drift. A plain cylinder does not hold position on air loss. The piston drifts and the fixed TPU bumper only decelerates near the stroke end. Use an external stop for a fail-safe hold.
Authorized Export Seller
Genuine AirTAC parts produced by AirTAC factory.
1-Year Warranty
Covers non-human-caused product damage.
Fast Dispatch
Standard models are processed and dispatched in 3-5 business days.
Fast Reply
Most inquiries answered within 7-8 hours.
Related AirTAC PBJ Pen-Size Cylinders
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