Round bottom blades come is sizes from 3" to 6" blades. Because they are contoured on the bottom, they require the use of a blade chuck to attach the blade to your drain cable. They have a thickness of .072 inches and a width of 1.00 inches. These drain knives are best used with 5/8" to 3/4" cable and have a 3/8" thread size.
Note: The round-bottom blades can only be used with the 7722 chuck assembly:
7722 Bronze Blade Chuck Assembly for 1” Wide Round-Bottom Blades