Airtac PTBR Single Acting Square Head Compact Cylinder PTBR8X40SR
The AirTAC Airtac PTBR Single Acting Square Head Compact Cylinder PTBR8X40SR 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, 40mm stroke; the return spring resets the rod when air is released.
- BoreØ8 mm
- Stroke40 mm
- Port sizeM5×0.8
- Front-mount threadM4×0.7
- Acting typePull, single acting
- ReturnSpring
- 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 PTBR Single Acting Square Head Compact Cylinder PTBR8X40SR
The AirTAC PTBR8X40SR is a JIS pen-size single-acting pull cylinder with a 40mm stroke. Air entering the M5x0.8 port retracts the rod, while an internal spring pushes it back out. This provides a fail-safe extended state during air loss, ideal for holding parts in place when pressure drops. It yields 12.4N of net pull at 0.5MPa and 19.9N at 0.7MPa.
You mount it directly via the front-cover M4x0.7 thread, eliminating extra brackets to save space on end-of-arm tooling. The SUS316L stainless barrel resists corrosion in tight jigs. A fixed TPU bumper cushions the stroke ends, and the built-in magnet (-S) supports reed or electronic switches for position sensing.
Airtac PTBR Single Acting Square Head Compact Cylinder PTBR8X40SR Technical Specifications
| Model | Airtac PTBR Single Acting Square Head Compact Cylinder PTBR8X40SR |
|---|---|
| Series | PTBR JIS pen-size front-mount cylinder |
| Bore size | Ø8 mm |
| Rod diameter | Ø4 mm |
| Stroke | 40 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 PTBR8X40SR
| PTBR | JIS pen-size front-mount single acting, pull type (spring extend) series. |
|---|---|
| 8 | Bore size in mm. |
| ×40 | 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 PTBR8X40SR Is Used
Fail-Safe Hold-Down Clamp
Clamps a workpiece with the rod extended by spring force, automatically releasing tension safely if the air supply drops.
Retract-to-Open Gate
Uses the direct M4x0.7 front-mount thread to bolt straight to a conveyor diverter, pulling the gate open on air.
Light Tensioning Jig
Maintains steady tension on a light filament or wire, retracting only when the M5x0.8 air port is pressurized.
Is the Airtac PTBR Single Acting Square Head Compact Cylinder PTBR8X40SR the Right Cylinder?
When sizing this 8mm bore, compare both neighbors. Dropping to a 6mm bore gives 7.1N net pull at 0.5MPa, while stepping up to a 10mm bore provides 23.5N. This PTBR8X40SR sits in the middle with 12.4N at 0.5MPa.
The 40mm stroke is well within the 60mm limit for this bore. Because the thin 4mm rod is built for coaxial thrust, add an external guide if your application involves off-axis loads.
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 PTBR8X40SR FAQ
The net pull force is 12.4N at 0.5MPa and 19.9N at 0.7MPa. Because it is spring-extended, a minimum pressure of 0.2MPa is required before the rod can retract. If air is lost, the spring forces the rod back out to a fail-safe extended position.
It mounts directly via an M4x0.7 thread on the front cover, with an R axial air inlet on the back. The -S suffix indicates a built-in piston magnet compatible with reed or electronic switches. The SUS316L stainless barrel ensures 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 are processed and dispatched in 3-5 business days.
Fast Reply
Most inquiries answered within 7-8 hours.
Related AirTAC PTBR Pen-Size Cylinders
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