These Alpha high speed steel (HSS) double ended panel drill bits have a titanium nitride coating (TiN) and are designed for use with rivets (10/box) Features: Double ended to last twice the lifetime 135° split point for fast drilling and M2 HSS for durability Titanium nitride coating to increase lubrication and reduce heat Stub double ended drill bits – quick reference Code Size Specs Qty 9D30 #30 for 3.2mm (1/8′′) rivets HSS TiN 10 9D20 #20 for 4.0mm (5/32′′) rivets HSS TiN 10 9D11 #11 for 4.8mm (3/16′′) rivets HSS TiN 10 Panel drill bits are sometimes referred to as stub drills or double enders. Single ended drill bits are also available.