IRWIN Assorted Woodboring Drill Bit VT Dimensions solid or engineered tongue and 309558677 solid or engineered tongue and groove flooring Dual LED light with an independent on off switch illuminate the work area Full length heat treated bit guards against bending in heavy duty applications Full length heat treated bit strengthens the twist where the greatest strain occurs All bits have a 4 1 2 In overall length Coarse screw point provides fast boring in hard and soft woods Single spur cutting edge scribes the circumference of the hole for a smoother finish Coarse screw point provides fast drilling in hard and soft woods Full length heat treated bit guards against bending in heavy duty applications