Design provides extra rigidity while boring
Wide lands keep bit straight as it bores
Flutes are ground behind the lands to funnel-
Chips to bit inside for cleaner/faster cut
Single spur cutting edges scribes hole
Bits have 4-1/2 In. twist & 7-1/2 In. overall length
Full length heated treated bit
3/8" Shank
Some of these are packaged with Irwin Sleeves
and some of them are packaged with the Master Mechanic Sleeves