Bosch High-Speed Steel Conical/Step Drill Bit 4-20 mm 65 mm 1/4" Hexagonal Shank

The Bosch HSS Conical / Step Drill Bit 4–20 x 65 mm is a one-piece HSS step drill bit designed for metalworking. It allows you to drill conical and stepped holes progressively in sheet metal and thin stock. High-speed steel gives it the hardness needed to cut cleanly without deforming the bit. The bit is rated for steel sheet, plastic, and various non-ferrous metals. The stepped profile produces accurate holes and reduces the risk of grabbing during operation. Operators can produce several hole sizes in one continuous motion, simplifying repetitive installation and fitting work.

A hexagonal shank holds the bit firmly in standard drill chucks. It is a dependent component and is used with handheld drills or stationary presses. The unified step profile lets users enlarge holes smoothly, and the progressive design leaves cleaner results than forcing standard bits through sheet material. An integrated format keeps the workspace tidy during complex assembly jobs, and fewer tool changes reduce downtime on repetitive fabrication tasks. Correct use requires matching the chuck speed to the workpiece material.

• 4–20 mm size range allows the user to drill progressively larger diameters in precise increments.
• 20 mm maximum drilling capacity in both steel and aluminium suits standard metal fabrication.
• 1/4" (6.35 mm) hex shank provides direct compatibility with keyless chucks and standard bit holders.
• 65 mm overall length offers adequate clearance for penetrating panels and enclosures without excess protrusion.
• Multi-material rating covers steel sheet, plastic, and non-ferrous metals including aluminium, copper, lead, and brass.