Features: 1.This is a HSS steel step cone drill titanium bit hole cutter. 2.Made from high quality HSS steel,anti-rust and durable. 3.With the Titanium coated to reduce friction and heat. 4.Easy to install and use. 3.It is very suitable for using to cut holes in a variety of materials including steel,brass,wood,plastic,etc. Descriptions: 1.This is a HSS steel step cone drill titanium bit hole cutter. 2.These step drill bits are ideal for variety of materials from metal, plastic, fiberglass to wood Specifications: Label: Yes Size (optional): 4-32mm, 4-20mm, 4-12mm,1 set(4-32mm+4-20mm+4-12mm) Color:Gold Handle type:Hex handle Handle diameter:6.35mm Total length:67mm/2.61in, 77mm/3in, 102mm/3.98in Weight:45g/150g Materail: HSS High Speed Steel ?Coating: Titanuim Package Includes:(optional) 1 x Step Drill Bits