Airtac PTBR Single Acting Square Head Compact Cylinder PTBR8X25R
The AirTAC Airtac PTBR Single Acting Square Head Compact Cylinder PTBR8X25R 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, 25mm stroke; the return spring resets the rod when air is released.
- BoreØ8 mm
- Stroke25 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 PTBR8X25R
The AirTAC PTBR8X25R is a JIS pen-size single-acting pull cylinder. Air entering the M5x0.8 port retracts the rod, while a spring pushes it back out. This provides a fail-safe extended state on air loss, ideal for tensioning or return-to-home tasks. It delivers 12.4 N of net pull at 0.5 MPa.
The slim SUS316L stainless body bolts directly to a fixture via the front-cover M4x0.7 thread, saving space on light end-of-arm tooling. A fixed TPU bumper cushions the stroke ends. Because pull acts on the smaller rod-side area, this 8 mm bore generates lower force than a matching push cylinder.
Airtac PTBR Single Acting Square Head Compact Cylinder PTBR8X25R Technical Specifications
| Model | Airtac PTBR Single Acting Square Head Compact Cylinder PTBR8X25R |
|---|---|
| Series | PTBR JIS pen-size front-mount cylinder |
| Bore size | Ø8 mm |
| Rod diameter | Ø4 mm |
| Stroke | 25 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 PTBR8X25R
| PTBR | JIS pen-size front-mount single acting, pull type (spring extend) series. |
|---|---|
| 8 | Bore size in mm. |
| ×25 | 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 PTBR8X25R Is Used
Tension Pull-Back
Applies constant spring tension to keep belts or light cables taut, using air only to release the pull.
Fail-Safe Hold-Down
Holds a workpiece securely with the rod extended; air retracts it, ensuring the clamp stays engaged if air drops.
Retract-to-Open Gate
Keeps a small access gate closed via spring force, opening the path only when compressed air pulls the rod back.
Is the Airtac PTBR Single Acting Square Head Compact Cylinder PTBR8X25R the Right Cylinder?
For sizing, the 8 mm bore yields 12.4 N net pull at 0.5 MPa and 19.9 N at the 0.7 MPa maximum. If your task needs less force, the 6 mm bore offers 7.1 N at 0.5 MPa; stepping up to the 10 mm bore provides 23.5 N. Plan for a safe working load of roughly 7 N, which is about 60 percent of the rated figure, to account for seal friction.
This model uses the R axial back cover for inline plumbing and lacks a sensor magnet. Remember the thin Ø4 mm rod is built for coaxial thrust, so add an external guide for off-axis loads. Confirm your front-mount thread engagement before 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 PTBR8X25R FAQ
It provides 12.4 N net pull at 0.5 MPa and 19.9 N at 0.7 MPa. Because it is spring-extended, a minimum operating pressure of 0.2 MPa is required to overcome the spring and retract the rod.
It mounts directly via the front-cover M4x0.7 thread. Air is plumbed through the R axial back cover inlet, which uses an M5x0.8 port, while the SUS316L barrel ensures durability in tight spaces.
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Covers non-human-caused product damage.
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Standard models usually ship in 3-4 days.
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Related AirTAC PTBR Pen-Size Cylinders
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