Machining PTFE Bronze 40

PTFE Bronze 40 is a PTFE (polytetrafluoroethylene) filled with 40 % bronze. The high metal content makes the material very wear- and compression-resistant, increases load capacity (PV value) and conducts the frictional heat well. This makes bronze PTFE the classic material for heavily loaded plain bearings, piston rings and sealing elements. Note: bronze PTFE is electrically dissipative (not an insulator), brown, and chemically less resistant than virgin PTFE because the bronze is attacked by many media.

PTFE Bronze 40 machines well – turning, milling, drilling and sawing give clean results; because of the bronze content we use sharp, wear-resistant tools and ensure dust/chip extraction. We consistently avoid overheating. This is how we reliably produce heavily loadable sliding, bearing and sealing parts – from single pieces to series production.

Bronze PTFE is worthwhile when high mechanical load, wear resistance and heat dissipation are required – for example:

• Heavily loaded plain bearings and bushes (incl. dry running)
• Piston rings and guides in compressors and pumps
• Sealing elements and guide bands in hydraulics/pneumatics
• Wear plates and parts under high surface pressure
• Applications requiring dissipative (antistatic) behaviour

PTFE materials are among the higher-priced engineering plastics; the bronze content increases the weight and thus the material cost per part. The price is mainly determined by semi-finished shape and dimension, material utilisation (offcut), machining effort and lot size. We are happy to quote binding prices on request based on your drawing.

Equally important are the limits of the material:

• Aggressive chemistry (acids, strong alkalis, oxidising media, ammonia) – bronze is attacked
• Electrical insulation required – bronze PTFE is dissipative (then virgin PTFE or GF)
• Food/drinking-water contact (metallic filler)
• Ultra-clean applications without metal abrasion
• Joining by welding – not possible for PTFE (machining only)

An honest assessment – and how the disadvantages can be mitigated in practice: Advantages:

Disadvantages:

Practical tip: PTFE Bronze 40 is the right choice for heavily loaded, heat-conducting sliding and bearing applications in neutral to mild media. If electrical insulation, maximum chemical resistance or food contact is required, virgin PTFE or glass-fibre-filled PTFE (GF) is the better choice. For highest load capacity and heat dissipation, PTFE Bronze 60 is the step up.

• Very high wear and compressive strength, high load capacity (PV)
• Good heat dissipation (higher sliding speeds possible)
• Low creep (cold flow)
• Low friction, -200 … +260 °C, non-flammable
• Electrically dissipative/antistatic
• Reduced chemical resistance (bronze is attacked)
• Not an electrical insulator (dissipative)
• Not for food/drinking-water contact (metal filler)
• Higher weight than virgin/GF PTFE
• Not melt-processable/weldable (machining only)