Graphite-Filled PTFE Seal — why this filler for this component
For a dynamic seal, graphite filling answers a specific problem: how to seal against a bore or rod you cannot afford to damage. Graphite runs at the lowest friction of the filled grades and will not abrade a plated or non-ferrous surface the way a glass-filled lip will.
Where Graphite-Filled PTFE Seal is used
Against a bronze-filled seal
graphite protects the counterface and runs with far less drag, but bronze resists extrusion at pressure and moves heat better. Choose graphite when the bore is soft or the actuator is friction-limited; choose bronze when the pressure is the problem.
Leakage develops gradually as the lip loses interference. Because friction is low, the seal generates little heat and tends to age slowly and predictably rather than failing abruptly.
Key properties
Compound
Graphite-filled PTFE, typically around 15% graphite
Duty
dynamic sealing on soft, plated or non-ferrous counterfaces
How it behaves here
Lower lip friction means less heat at the sliding contact and less drag on the actuator, which matters on long-stroke or high-cycle equipment. The graphite also helps the lip bed in without the initial scoring phase a harder filler can cause.
Where it does not belong
Extrusion resistance is lower than bronze- or glass-filled seals. At high pressure with a generous extrusion gap the lip will be forced into the clearance, so this grade suits moderate-pressure sealing rather than heavy hydraulics.
Specifications
| Property | Value |
|---|---|
| Compound | Graphite-filled PTFE, typically around 15% graphite |
| Duty | Dynamic sealing, moderate pressure |
| Form supplied | Machined to seal drawing |
| Governing factor | Low lip friction and counterface protection |
| Counterface | Suits plated, non-ferrous and softer bores |
| Not suitable for | High-pressure hydraulics with a wide extrusion gap |
Manufacturing process
Compression moulded from roughly 15% graphite compound, sintered, then machined to the seal drawing.
Material selection notes
Lower lip friction means less heat at the sliding contact and less drag on the actuator, which matters on long-stroke or high-cycle equipment. The graphite also helps the lip bed in without the initial scoring phase a harder filler can cause.
How to specify your order
Against a bronze-filled seal: graphite protects the counterface and runs with far less drag, but bronze resists extrusion at pressure and moves heat better. Choose graphite when the bore is soft or the actuator is friction-limited; choose bronze when the pressure is the problem.
Quality checks and inspection
Dimensions are verified on CMM against your drawing. Filler content and sintered density are checked per ASTM D792, with tensile and elongation per ASTM D4894. A mill test certificate stating the lot, filler content and measured values ships with the order.
Ordering and export documentation
Check the extrusion gap against the working pressure before fitting — this grade is less tolerant of a wide gap than a bronze-filled lip. Counterface finish should follow the seal drawing.
Export packing and lead time
HEMSUN is a DGFT IEC registered exporter (Government of India). Commercial invoice, packing list and certificate of origin accompany international despatch.
Storage and handling
Leakage develops gradually as the lip loses interference. Because friction is low, the seal generates little heat and tends to age slowly and predictably rather than failing abruptly.
Compliance & Standards
HEMSUN is a DGFT IEC registered exporter (Government of India). Filler content and sintered density are verified per ASTM D792 on each batch, with tensile and elongation checked per ASTM D4894.
Frequently Asked Questions
What Graphite-Filled PTFE Seal options does HEMSUN manufacture?
For a dynamic seal, graphite filling answers a specific problem: how to seal against a bore or rod you cannot afford to damage. Graphite runs at the lowest friction of the filled grades and will not abrade a plated or n…
Can you supply Graphite-Filled PTFE Seal for OEM and export orders?
Yes. We support prototype lots, recurring OEM programmes, and export packing with material certificates and dimensional inspection reports on request. Typical RFQ response is within one business day when drawings are complete.
How do I request a quote for Graphite-Filled PTFE Seal?
Send material grade, dimensions or drawing, quantity, application media, and operating temperature/pressure via https://hemsun.com/contact. Our engineering team confirms manufacturability, lead time, and pricing.
