Material & Alloy Index
Metals, elastomers, fabrics, finishes & weaves used across GQI's product lines: descriptions, surface-finish Ra reference and elastomer selection.
Metals, elastomers, fabrics, finishes & weaves used across GQI's product lines: descriptions, surface-finish Ra reference and elastomer selection.
| Finish | Method | Typical Ra |
|---|---|---|
| Mill / 2B | Cold-rolled, annealed, pickled (as-supplied) | ~0.1–0.5 µm (4–20 µin) |
| No. 3 | Coarse ground (~100–120 grit) | ~0.6–1.0 µm (25–40 µin) |
| No. 4 (brushed) | Polished ~150–180 grit: standard sanitary | ~0.4–1.0 µm (16–40 µin) |
| No. 6 / 7 | Fine satin → bright polish | ~0.1–0.5 µm (4–20 µin) |
| ASME BPE SF1 / SF2 / SF3 | Mechanically polished | ≤ 0.51 / 0.625 / 0.75 µm (20 / 25 / 30 µin) |
| ASME BPE SF4 / SF5 / SF6 | Electropolished | ≤ 0.38 / 0.51 / 0.625 µm (15 / 20 / 25 µin) |
GQI weld-finish labels map roughly: Industrial ≈ as-welded/mill · Commercial ≈ dressed · Sanitary ≈ No.4 / SF1 · Dairy ≈ Ra ≤ 0.8 µm · Pharma ≈ SF4 electropolished. (Hecht SP01: O4–O5 industrial, O6 Ra<1.6, O7/O8 Ra<0.8, O9 electropolished.)
| Material | Typical temp range* | Best for | Avoid |
|---|---|---|---|
| EPDM | −40 to +150 °C | Water, steam, CIP, weather; FDA | Oils, fuels, hydrocarbons |
| Silicone (VMQ) | −60 to +200 °C | Wide temp, clean/FDA/pharma | Abrasion, superheated steam |
| Nitrile / NBR | −30 to +120 °C | Oils, fuels; economical | Ozone, UV, ketones |
| FKM / Viton | −20 to +200 °C | Chemicals, fuels, heat | Hot water/steam, ketones, amines |
| PTFE / FEP | −200 to +260 °C | Almost all chemicals; non-stick | Needs elasticity (not a spring) |
| Polyurethane (PU) | −30 to +80 °C | Abrasion, flex, inflatable seals | Hot water/steam, strong acids/bases |
| Natural rubber | −50 to +80 °C | Abrasion, impact, resilience | Oils, ozone, sunlight |
*Typical ranges: actual limits depend on the specific compound, pressure and media. Confirm chemical compatibility & FDA/USP grade with the seal supplier. Reference only.