Airtac PTBR Single Acting Square Head Compact Cylinder PTBR8X50R
The AirTAC Airtac PTBR Single Acting Square Head Compact Cylinder PTBR8X50R is a single acting, pull type (spring extend) pen-size mini cylinder with direct front-cover mounting (M4×0.7 thread). A single air port drives the pull stroke on a Ø8mm bore, 50mm stroke; the return spring resets the rod when air is released.
- BoreØ8 mm
- Stroke50 mm
- Port sizeM5×0.8
- Front-mount threadM4×0.7
- Acting typePull, single acting
- ReturnSpring
About the Airtac PTBR Single Acting Square Head Compact Cylinder PTBR8X50R
The AirTAC PTBR8X50R is a JIS pen-size single-acting pull cylinder with a 50 mm stroke and 8 mm bore. Air entering the M5x0.8 port retracts the rod, while an internal spring pushes it back out, ensuring fail-safe extension on air loss. It delivers 12.4 N of net pull at 0.5 MPa and 19.9 N at 0.7 MPa, with the spring force already deducted.
You bolt this directly to a fixture via the front-cover M4x0.7 thread, eliminating extra brackets. The SUS316L stainless barrel resists corrosion in tight spaces. Because pull acts on the rod-side annular area, this usable force is lower than a matching push cylinder. A fixed TPU bumper cushions the stroke ends, requiring meter-out exhaust if moving real tooling mass at higher speeds.
Airtac PTBR Single Acting Square Head Compact Cylinder PTBR8X50R Technical Specifications
| Model | Airtac PTBR Single Acting Square Head Compact Cylinder PTBR8X50R |
|---|---|
| Series | PTBR JIS pen-size front-mount cylinder |
| Bore size | Ø8 mm |
| Rod diameter | Ø4 mm |
| Stroke | 50 mm |
| Acting type | Single acting, pull type (spring extend) |
| Front-mount thread | M4×0.7 |
| Port size | M5×0.8 |
|---|---|
| Operating pressure | 0.2 – 0.7 MPa |
| Proof pressure | 1.2 MPa |
| Temperature | -20 to +70 °C |
| Speed range | 50 – 800 mm/s |
| Return | Return spring (pull by air) |
| Max standard stroke | Up to 60 mm |
The spring holds the rod extended; applying air retracts it, and removing air lets the spring push the rod back out. Front cover carries the mounting thread (M4×0.7); barrel is SUS316L. Forces below are NET spring-deducted values. Confirm against the product label.
Net Pull Force (Ø8mm)
| Pressure | Net pull force |
|---|---|
| 0.5 MPa | 12.4 N |
| 0.7 MPa (max) | 19.9 N |
These are usable pull forces after the return spring is subtracted, from the AirTAC single-acting thrust table. Minimum operating pressure is set by the spring, so this model needs at least the lower pressure shown to move.
Model Code: Airtac PTBR Single Acting Square Head Compact Cylinder PTBR8X50R
| PTBR | JIS pen-size front-mount single acting, pull type (spring extend) series. |
|---|---|
| 8 | Bore size in mm. |
| ×50 | Stroke length in mm. |
| S | Built-in magnet for magnetic-switch position sensing (omit = no magnet). |
| R | Back cover: R axial inlet (bore-dependent). |
Mounting: direct front-cover thread (M4×0.7). Related PBR-family variants: PBR (double acting), PSBR (single-acting push).
Where the Airtac PTBR Single Acting Square Head Compact Cylinder PTBR8X50R Is Used
Hold-Down Clamp
Uses spring pressure to keep a delicate part clamped. Air pulls the rod back to release the component, ensuring the clamp opens safely if the air supply drops.
Retract-to-Open Gate
Blocks items on a line by default. A brief air pulse retracts the gate to let products pass, and the spring closes it automatically when air stops.
Light Tensioner
Maintains steady tension on a wire or film. The spring holds the material taut, while air retracts the unit to slacken the line for splicing or loading.
Is the Airtac PTBR Single Acting Square Head Compact Cylinder PTBR8X50R the Right Cylinder?
For an 8 mm bore at 0.5 MPa, you get 12.4 N of usable pull. If your jig needs less force, stepping down to a 6 mm bore yields 7.1 N. If you need more pull, a 10 mm bore provides 23.5 N. Plan for a safe working load of roughly 7 N (about 60 percent of the 0.5 MPa rating) to account for seal friction and smooth travel.
This direct front-mount design saves space, but the thin 4 mm piston rod is built strictly for coaxial thrust. Over this 50 mm stroke, any off-axis load requires an external guide or linear bearing to prevent side-loading damage. Confirm your M5x0.8 air line and front M4x0.7 bolt engagement during ordering.
Quick checklist
- ✓ Net pull force at your working pressure
- ✓ Bolt directly through the front cover (M4×0.7)
- ✓ Only one air line / solenoid needed
- ✓ Fail-safe extend on air loss
- ✓ Magnet (S) for sensors?
- ✓ Stroke ≤ 60 mm (single-acting limit)
Installation & Maintenance Notes
- check Use clean air filtered to 40µm or finer.
- check Keep within 0.2 – 0.7 MPa operating pressure.
- check Allow for spring force in the stroke direction.
- check Match bolt size and engagement to the front thread.
- check Do not add an external return mechanism.
- check Keep the load coaxial; avoid side load on the thin rod.
Airtac PTBR Single Acting Square Head Compact Cylinder PTBR8X50R FAQ
It provides 12.4 N of net pull at 0.5 MPa and 19.9 N at 0.7 MPa. Because it is a spring-extend cylinder, a minimum pressure of 0.2 MPa is required before the rod can retract. If air is lost, the spring forces the rod back out.
It mounts directly via the front-cover M4x0.7 thread. The air inlet uses an R axial back cover with an M5x0.8 port, keeping plumbing in a straight line. The SUS316L stainless barrel provides durability in compact spaces.
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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.
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Most inquiries answered within 7-8 hours.
Related AirTAC PTBR Pen-Size Cylinders
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