PTFE vs PVDF Fasteners: Chemical Application Selection Guide
PTFE vs PVDF Fasteners: How to Choose
PTFE (polytetrafluoroethylene) and PVDF (polyvinylidene fluoride) are the two most commonly used high-performance corrosion-resistant fastener materials in the chemical industry. Both offer excellent chemical resistance but differ in performance focus.
1. Temperature Performance
PTFE: -200°C to +260°C, the widest temperature range. PVDF: continuous ~150°C, short-term up to 170°C. For extreme low or high temperatures, choose PTFE.
2. Chemical Resistance
PTFE is the most chemically inert, resisting almost all chemicals including concentrated acids, strong bases and oxidizers. PVDF resists most acids, alkalis and organic solvents but is sensitive to concentrated sulfuric acid, ketones and esters.
3. Mechanical Strength
PVDF is significantly stronger than PTFE (tensile strength roughly 3x), better suited for load-bearing fastener applications. PTFE is softer, ideal for gaskets and low-load sealing.
4. Purity
Semiconductor-grade PVDF is widely used in electronics and pharmaceutical industries. PTFE also offers high-purity grades. Both meet FDA food-contact requirements.
5. Cost
PVDF is typically more economical. When performance is sufficient, PVDF offers better value; extreme chemical or wide-temperature applications require PTFE.
Selection Guide
- High temperature (>170°C) or cryogenic → PTFE
- Concentrated acids and strong oxidizers → PTFE
- Load-bearing chemical assemblies → PVDF
- Semiconductor/pharma high purity → High-purity PVDF or PTFE
Contact the FASTKING engineering team for specific recommendations.