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304 対 316L ステンレス鋼: 塩水噴霧と腐食の比較
ステンレス鋼板の仕上げ: 2B, BA, No.4とミラーの説明
When you order stainless sheet, the finish code is not a cosmetic detail — it determines how the sheet forms, how it cleans, and how long it lasts. 2B, BA, No.4 brushed and mirror (No.8) look similar to the untrained eye but perform very differently. This guide explains each finish and when to specify it.
The Common Finishes
2B is the standard matte silver finish, produced by cold rolling and light skin pass. It is the default for most industrial applications, with a smooth but non-reflective surface that forms and welds well. BA (光輝焼鈍) is a brighter, near-mirror finish produced by annealing in a controlled atmosphere, used for appliances, food equipment and decorative trim. No.4 is a directional brushed finish with fine parallel lines, the classic “brushed stainless” look used in kitchens and elevators. No.8 is a true mirror polish, used for decorative panels, reflectors and architectural features. 私たちのを参照してください 304 2Bシート.
| 仕上げる | 外観 | Reflectivity | 一般的な使用方法 |
|---|---|---|---|
| 2B | Matte silver | 低い | 産業用, 溶接, 形にする |
| BA | 明るい, near-mirror | Medium-high | Appliances, 食品機器 |
| No.4 | つや消し, directional | 中くらい | Kitchens, エレベーター, トリム |
| No.8 | Mirror polish | 非常に高い | 装飾的な, reflectors |
Why Finish Matters Beyond Looks
2B is the most formable and weldable finish — scratches from stamping disappear under further processing. No.4 brushed hides fingerprints and minor wear, making it the default for kitchen and public surfaces. Mirror finish looks premium but shows every scratch and fingerprint, so it is used only where it is not touched. For food processing, 2B or BA are preferred because they are easy to clean and the matte surface does not show water spots. For architectural facades, No.4 brushed or etched finishes hide weathering better than mirror.
Buying Advice
Always specify the finish in the purchase order, because “304 シート” without a finish defaults to 2B, which may not be what you want for a decorative project. Brushed No.4 is directional — specify the grain direction (horizontal or vertical) for facade panels. Mirror finish is an extra processing step after the sheet, so it costs 2 – 3× more than 2B. For industrial fabrication, 2B is the right default; upgrade only when the visible surface needs it.
