Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-20S
The AirTAC Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-20S 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 PBJ12X125-20S
The AirTAC PBJ12X125-20S is a double-acting, double-rod pen-size mini cylinder with a 20mm adjustable stroke window. A rear adjuster screw shortens the retract end, giving an effective range of 105-125mm. The extend end remains fixed.
The slim SUS304 stainless body saves space in tight jigs. A fixed TPU bumper decelerates the last few millimeters of travel. The built-in piston magnet works with AirTAC reed or electronic switches. This 12mm bore uses an M5x0.8 air port and an M10x1.0 rod-end thread.
Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-20S Technical Specifications
| Model | Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-20S |
|---|---|
| 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 PBJ12X125-20S
| 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 PBJ12X125-20S Is Used
Changeover Fixtures
Quickly dial in the retract stop from 105 to 125mm during product changeovers without machining new pins or swapping cylinders.
Trial Positioning Stops
Set precise back positions for test probes and sensing plungers, locking the nut once the exact 105-125mm travel is found.
Variable-Depth Insertion
Fine-tune the extend-and-return depth for pressing pins or plugs on the fly, using the rear screw to shorten the retract end.
Is the Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-20S the Right Cylinder?
Select this 12mm model when you need on-machine tuning of the back position within a 105-125mm window. Remember that only the retract end is adjustable; the extend stroke is fixed. Always re-tighten the M5x0.8 adjuster lock nut after setting to prevent vibration drift.
Confirm your ordering essentials: 12mm bore, 125mm nominal stroke, 20mm adjuster window, built-in magnet (S), and any mounting brackets (LB or FA). The Ø5mm rod is built for coaxial thrust; over this 125mm stroke, add an external guide or linear bearing if the load is off-axis to prevent rod bending.
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 PBJ12X125-20S FAQ
The 20mm rear adjuster window gives an effective stroke range of 105-125mm by shortening the retract end; the extend end is fixed.
A rear M5x0.8 adjuster screw shortens the retract stroke; you must re-tighten the lock nut after setting to prevent vibration drift. A plain PB-type cylinder does not hold position on air loss—the piston drifts and the fixed TPU bumper only decelerates near stroke end. Use an external rod lock for fail-safe holding.
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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