PTFE (Teflon) Sheet & Rod for Canadian Fabrication
Comprehensive technical specification for PTFE (Teflon) sheet and rod stock, covering Canadian standard sizing, machining parameters, common defects, and storage guidelines for industrial fabrication and CNC machining.
Material Overview & Common Uses
PTFE (Polytetrafluoroethylene), commonly known by the brand name Teflon, is a high-performance engineering plastic prized for its exceptional chemical resistance, low coefficient of friction, wide operating temperature range (-200°C to +260°C), and excellent electrical insulation properties. In Canadian fabrication shops, PTFE is used for non-stick liners, gaskets, seals, bearings, slide pads, electrical insulators, and chemical-resistant components. It is available in sheet, rod, and tube forms, with sheet being the most common for CNC routing and sawing, and rod for turning and milling on lathes and mills. PTFE is not hygroscopic, does not absorb moisture, and is self-lubricating, making it ideal for food processing, pharmaceutical, and semiconductor applications where contamination must be avoided.
Core Technical Properties & Sizing
Physical & Mechanical Properties
| Property | Value | Notes |
|---|---|---|
| Density | 2.15–2.20 g/cm³ | Virgin grade |
| Tensile Strength | 20–35 MPa | Virgin; 15–25 MPa reprocessed |
| Elongation at Break | 200–400% | Virgin |
| Coefficient of Friction | 0.04–0.10 | Static — among lowest of any solid material |
| Operating Temperature | −200°C to +260°C | Continuous; short-term peaks to 300°C |
| Dielectric Strength | 60–80 kV/mm | At 0.1 mm thickness |
| Water Absorption | <0.01% | 24 hours, ASTM D570 |
Canadian Standard Sheet Sizes (inches)
| Dimension | Standard Sizes |
|---|---|
| Sheet | 48″ × 48″, 48″ × 96″, 60″ × 60″, 60″ × 120″ |
| Thickness | 1/16″, 1/8″, 3/16″, 1/4″, 3/8″, 1/2″, 3/4″, 1″, 1‑1/2″, 2″ |
| Metric equivalents | 1220 × 1220 mm, 1220 × 2440 mm, 1524 × 1524 mm, 1524 × 3050 mm; thicknesses 1.5, 3, 5, 6, 10, 12, 19, 25, 38, 50 mm |
Standard Rod Diameters
| System | Diameters |
|---|---|
| Inches | 1/4″, 3/8″, 1/2″, 5/8″, 3/4″, 1″, 1‑1/4″, 1‑1/2″, 2″, 2‑1/2″, 3″, 4″ |
| Metric | 6, 10, 12, 16, 20, 25, 30, 40, 50, 60, 75, 100 mm |
Tolerances & Grades
| Parameter | Tolerance / Detail |
|---|---|
| Sheet thickness ( < 1/4″ ) | ±0.005″ |
| Sheet thickness ( 1/4″ to 1/2″ ) | ±0.010″ |
| Sheet thickness ( > 1/2″ ) | ±0.020″ |
| Rod diameter ( < 1″ ) | ±0.002″ |
| Rod diameter ( 1″ to 2″ ) | ±0.005″ |
| Rod diameter ( > 2″ ) | ±0.010″ |
| Flatness (sheets up to 1/2″) | 0.010″ per foot |
| Rod length | 6 ft (1.83 m) or 10 ft (3.05 m) random |
| Grades | Virgin (natural white), Reprocessed (off‑white/grey), Glass‑filled (15–25%), Carbon‑filled (antistatic/conductive) |
Machinability, Tooling & Feeds
PTFE is soft, gummy, and has a low melting point (327°C), requiring sharp tooling and careful chip control to avoid melting, smearing, or burr formation. Use HSS or carbide tools with polished flutes and positive rake angles (10–15°).
| Operation | Tooling | Speeds / Feeds | Critical Notes |
|---|---|---|---|
| CNC Routing | Single‑flute O‑flute or compression bits | Chip load 0.002–0.005 in/tooth, 12,000–18,000 RPM, 100–200 IPM | For 1/4″ sheet; avoid climb milling on thin sections |
| Sawing | Carbide‑tipped blades, 10–14 TPI | 3,000–4,000 SFM | Zero or negative hook angle |
| Turning | HSS or carbide inserts, sharp edge | 0.005–0.015 in/rev feed, 0.020–0.100 in DOC, 200–400 SFM | Use coolant mist or air blast to prevent heat buildup |
| Tapping | Thread‑forming taps or heli‑coils | — | PTFE is not suitable for conventional tapping |
| Laser Cutting | — | — | Produces toxic fumes (HF gas) — requires proper ventilation and fume extraction |
Deburring is critical: use a sharp knife or fine abrasive pad; do not use heat. PTFE is not hygroscopic, so no pre‑drying is required.
Common Defects & Quality Control
| Defect | Description | Quality Action |
|---|---|---|
| Porosity | Visible pinholes or voids, especially in reprocessed grades | Reject if present in sealing applications |
| Surface Contamination | Oil, grease, or dust embedded during manufacturing | Can cause bonding failures; clean or reject |
| Warpage | Sheets bow or cup due to residual stress | Check flatness with a straightedge; reject if out of tolerance |
| Crazing | Fine surface cracks from excessive stress or thermal shock | Reject for structural parts |
| Discoloration | Yellowing or brown streaks from thermal degradation | Reduced mechanical properties; reject for critical use |
| Thickness Variation | Out‑of‑tolerance sheets cause fit issues | Measure with micrometer at four corners and center |
| Edge Cracking | From rough handling or poor cutting | Trim before use; reject if crack length exceeds 1/8″ |
QC checks: Verify density by weighing a known volume; perform a simple tensile test on a coupon; check chemical resistance by immersing a sample in acetone (should not swell or dissolve). For critical applications, request a material certificate (C of C) from the supplier.
Storage, Handling & Racking Guidelines
Store PTFE sheets flat on a clean, dry surface away from direct sunlight and UV sources (UV causes embrittlement). Ideal temperature: 15–25°C, humidity <60%. Do not stack heavy items on top of sheets to avoid permanent deformation. Rods should be stored horizontally on racks with full-length support to prevent bowing. Use protective interleaving (kraft paper or plastic film) between sheets to prevent surface scratches. Avoid contact with sharp edges or abrasive surfaces. For long-term storage, wrap in polyethylene film to keep dust-free. Handle with clean gloves to avoid oil transfer. Do not store near open flames or high-heat sources (PTFE is non-flammable but can decompose above 400°C). Racking: use cantilever racks for rods, and flat shelving for sheets. Label each piece with grade, thickness, and date received. First-in-first-out (FIFO) rotation is recommended to avoid age-related property changes (though PTFE has indefinite shelf life if stored properly).