Maximum Bore Diameter: 60 mm. Our Boring Tool sets are ideal for CNC Milling. Complete sets of boring heads and shanks in a range of sizes The boring head has a diameter of 40 mm. Boring Head Kits – 38mm - ABM Tools Lathe Boring Head With Chisels Boring Head 9 Piece Set - Ring Turning And More HSS Chisel Set Centre Distance between the holes: 11 mm., Transverse hole: 8 mm., Verfahrweg: 11 mm., Minimum bore: 8 mm. Boring Head Set In addition, range are the set 3 piece chisel set (HSS with 8 mm Shaft), two Drehlinge (5 and 8 mm), one 45 ° extension cable with 5 mm Driver and Allen key for changing the tool., SOCKET bore: 8 mm. Included in the box contents include 3 photographs.