Carbon - Blue Steel Knives (Aogami 1 and 2) 青鋼 $$$$

About Blue Steel Knives (Aogami #1 and #2) - Carbon Steel

Sharpness　★★★★★ (5/5)

Hardness/durability　★★★★★ (5/5)

Edge retention ★★★★★ (5/5)

Ease of sharpening　★★★★☆ (4/5)

Rust resistance　★★★☆☆ (3/5)

Manufactured by Hitachi Metals,Ltd. Contains Carbon 1.3%, adding tungsten 1.5% and Chromium 0.4% to White steel.Rockwell Hardness 61-64 HRC.

Blue Steel （青鋼）is known as the highest sharpness and durability. Above the level of White Steel, Blue Steel contains smallest impurities as well as additional chrome and tungsten which makes the knives strong to wear and tear. With this mixture, Blue Steel is an ideal material for Japanese cutlery products. 

The only downside of Blue steel is that it’s not rust resistant as it contains high amount of carbon so that it requires users a good maintenance practice.