Westcott #11 Hobby Knife Refill Blades. #11 Hobby Knife Refill Blades 5pk Titanium Bonded blades are 3x harder than steel and will stay sharper longer Corrosion resistant for longer blade life Perfect for cutting craft paper, precision cutting and detail work Complete with a manufacturers limited lifetime warranty #11 replacement blades for hobby knife item #13974. Pack of 5 Refills