Drill bit set Top Tools HSS cylinder 4 mm 10 pcs (60H440)

Set of 10 Top Tools HSS cylinder 4 mm drill bits designed for reliable metal drilling. These cylindrical high-speed steel (HSS) bits are manufactured for consistent cutting performance and wear resistance, suitable for use in handheld drills and drill presses. The set is intended for producing precise through-holes in steel, iron and other ferrous materials in workshop, maintenance and fabrication applications.

Advantages

The HSS material offers high hardness and heat resistance for longer tool life during repeated metal drilling. A straight cylindrical shank ensures stable clamping in standard chucks and reduces runout, while the 4 mm diameter provides a balance between accuracy and drilling speed. Supplied as a 10-piece set, the bits allow quick replacement and reduce downtime for small to medium drilling tasks.

Suitable for

• Drilling through steel and iron plates
• Workshop and maintenance tasks
• Fabrication and assembly of metal parts
• Use with handheld drills and drill presses

Key specifications

• Material: High-speed steel (HSS)
• Shank type: Cylindrical (straight) shank for standard chucks
• Diameter: 4 mm
• Quantity: 10 pieces per set
• Primary use: Through-holes in ferrous metals

How to use

Select a suitable drill speed and clamping method for the 4 mm HSS bit and secure the workpiece. Fit the cylindrical shank into the drill chuck and tighten securely. For through-holes in steel or iron, start with a center punch if precise positioning is required, apply steady feed pressure and use cutting fluid for improved cooling and chip evacuation when drilling thicker or harder materials. Retract the bit occasionally to clear chips and avoid overheating.

Usage recommendations

Use recommended drill speeds for HSS in ferrous metals (moderate RPM), apply cutting fluid on thicker sections, and replace bits when wear or chipping reduces hole quality. Store the set in a dry place to prevent corrosion and keep bits organized to maintain their cutting edges.