440A 7Cr17 stainless steel flat

Type 440A isa higher grade of cutlery steel, with more carbon in it, which allows for much better edge retention

Type 440—a higher grade of cutlery steel,  similar steel grade is called 7Cr17 or 7Cr17MoV in China. with more carbon in it, which allows for much better edge retention when the steel is heat-treated properly. It can be hardened to around Rockwell 58 hardness, making it one of the hardest stainless steels. Due to its toughness and relatively low cost, most display-only and replica swords or knives are made of 440 stainless. Also known as razor blade steel. Available in four grades: 440A, 440B, 440C, and the uncommon 440F (free machinable). 440A, having the least amount of carbon in it, is the most stain-resistant; 440C, having the most, is the strongest and is usually considered a more desirable choice in knifemaking than 440A except for diving or other salt-water applications.

Chemica composition:

Carbon		0.68
Chromium		16 - 18
Iron		Balance
Manganese		1 max
Molybdenum		0.75 max
Phosphorus		0.04 max
Silicon		1 max
Sulphur		0.03 max

440A 7Cr17 stainless steel flat