Features.- High speed steel, hard and sharp.- Quick chip removal and fast drilling.- Can open two holes at once for easy work.- Smooth, efficient drilling with smooth hole walls and unobstructed chip removal.- Specially designed for opening sliding door frame holes for door frame processing, sliding door vertical frame processing, ironwork, aluminium alloy, wood, light alloy processing.Specification.Material: HSSAvailable sizes: 4-8/5-9/5-10/6-10/8-12mmSpecification:Material: Tungsten CarbideShank Dia: 3.175mm(1/8'')Overall Length: 38mmApplication: Suitable for processing PCB, normal FR-4, CEM-3 boards, environmental protection board, SMT, CNC, molds, plastic, Circuit board, carbon fiber, composite board, and so on.Features:Precision machining by high accurate equipment;With good milling and cutting performance, ensuring high efficiency;High hardness, wear resistance, and intensity; anti-bending;To remove chips, with big space and small resistance; Smooth chip removal, less heating value, to reduce pollution;Sharp cutting edge, reduce cutting force, lower breaking rate and improve the quality of hole wall;Symmetrical cutting blade, help to high effective cutting, avoiding drilling offset.