Ontario Knife Rat Folding Knife Black Blade Plain OK. This knife by Ontario Knife has a blade length of 3.5 inches with a satin finish over AUS-8 steel. The satin coat finish gives the Ontario Knives Rat Folding Knife a sleek professional look. When you need a knife that is built for durability and can handle just about anything you need the Ontario Knife Rat AUS-8 Folding Knife. Specifications for Ontario Knife Rat Folder - Satin: Hardness: 58-59 HRC Blade Thickness: .12in (.3cm) Blade Length: 3.5in (8.89cm) Overall Length: 8.5in (21.6cm) Features of Ontario Knife Rat Folding Knife: Folding Satin Blade Finish Flat Blade Grind AUS-8 Blade Package Contents: Ontario Knife Rat Folding Knife Ontario Knife OK8846: Rat Folding Knife Black Blade Plain