Drill Core and Square Hole Woodworking Drill Kit Set.

Material: High-Speed Steel

Application: used for woodworking punching
Heat treatment, HRC48-50, high hardness.
Drilling core is lengthened, concentricity is high.
Use with mortising chisel, if you extend the square hole manually, you need will have to use electric drill, hammer and other tools.
The dimension of each drill refers to the length of the square hole drilled by the square hole.
The cylinder diameter of the clamped portion is 19mm/0.74inch.
The square hole drilling core are more than 210mm long drilling core.

Choose either:

4pc Set: 6.4mm, 8mm, 9.5mm and 12.7mm. $99.50

7pc Set: 6.4mm, 8mm, 9.5mm, 10mm, 12.7mm, 14mm and 16mm. $187.70