Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-50S
The AirTAC Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-50S is a double-acting pen-size mini cylinder with a rear adjuster screw that shortens the retract end of the stroke. On a Ø12mm bore it gives a nominal 125mm stroke with a 50mm fine-adjustable window — settable from 75 to 125mm, so you set the end position without changing hardware.
- BoreØ12 mm
- Nominal stroke125 mm
- Adjust window50 mm
- Effective range75–125 mm
- Port sizeM5×0.8
- Acting typeDouble acting
About the Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-50S
The AirTAC PBJ12X125-50S is a double-acting, single-rod pen-size mini cylinder with a 50mm adjustable stroke window. A rear M5x0.8 adjuster screw shortens the retract end, giving an effective stroke range of 75-125mm from the 125mm nominal length. Output force is completely unaffected by the adjustment, delivering 56.5N push and 46.7N pull at 0.5 MPa, identical to a standard PB series cylinder.
Built with a SUS304 stainless barrel and a slim 12mm body, it saves space in tight jigs and end-of-arm tooling. The M5x0.8 air port and Ø5mm rod keep the envelope small, while the built-in magnet (-S) supports reed or electronic switches. A fixed TPU bumper cushions the extend and retract ends. For real-world sizing, plan for a safe working load of roughly 34N (about 60% of the 0.5 MPa push figure) to account for seal friction and smooth travel.
Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-50S Technical Specifications
| Model | Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-50S |
|---|---|
| Series | PBJ JIS pen-size adjustable-stroke cylinder |
| Bore size | Ø12 mm |
| Rod diameter | Ø5 mm |
| Nominal stroke | 125 mm |
| Adjustable window | 50 mm (75–125 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 |
The adjuster shortens only the retract end; the extend end is fixed. Force is unchanged from the standard PB double-acting cylinder. Confirm the set position against the product label before installation.
Theoretical Output Force (Ø12mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 56.5 N | 46.7 N |
| 0.7 MPa (max) | 79.1 N | 65.4 N |
Adjusting the stroke does not change output force — these are the same values as the standard PB double-acting cylinder of the same bore. Size with a friction margin.
Model Code: Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-50S
| PBJ | JIS pen-size adjustable-stroke mini-cylinder series. |
|---|---|
| 12 | Bore size in mm. |
| ×125 | Nominal stroke length in mm. |
| -50 | 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 PBJ12X125-50S Is Used
Changeover Fixtures
Dial in the exact retract distance during product changeovers. Set the rear screw anywhere from 75 to 125mm without swapping hardware.
Variable-Depth Insertion
Tune press depth on the machine. The adjuster modifies the back position without reducing the 56.5N push force at 0.5 MPa.
Trial Stop Positioning
Use the 50mm window to test multiple retract stops during prototyping. The fixed TPU bumper cushions the end of travel.
Is the Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-50S the Right Cylinder?
This 12mm bore provides 56.5N push at 0.5 MPa. If you need less force, the 10mm bore offers 39.3N push; if your fixture requires more thrust, step up to the 16mm bore for 100.5N push. Remember that only the retract position is field-settable via the rear screw—the extend end remains fixed. Always re-tighten the lock nut after tuning to prevent vibration drift.
Confirm your ordering essentials: 12mm bore, 125mm nominal stroke, -50mm window, built-in S magnet, and any LB or FA mounting hardware. Because the rod is a slender Ø5mm over a 125mm stroke, add an external guide or linear bearing for any off-axis loads to prevent side-load damage.
Quick checklist
- ✓ Need to fine-tune the end position on site
- ✓ Retract end sits within 75–125 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 The adjuster shortens the retract end only.
- 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 PBJ12X125-50S FAQ
The effective stroke range is 75-125mm (nominal 125mm minus up to 50mm). Force is identical to a standard PB cylinder: 56.5N push and 46.7N pull at 0.5 MPa, or 79.1N push and 65.4N pull at the 0.7 MPa maximum. Adjusting the stroke does not alter these force figures.
A 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. The cylinder does not hold position on air loss—the piston drifts, so an external rod lock or stop is required 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 usually ship in 3-4 days.
Fast Reply
Most inquiries answered within 7-8 hours.
Related AirTAC PBJ Pen-Size Cylinders
Request a Quote for Airtac PBJ Adjustable Pen-Type Cylinder PBJ12X125-50S
Send us the quantity and destination. We confirm price, stock and lead time — usually within 7-8 hours.