Drill bit set Proline 77841K — metal, Ø 4.1 mm, length 75 mm, 2 pcs

Proline 77841K drill bit set — two HSS metal drill bits with a nominal diameter of 4.1 mm and a length of 75 mm, supplied in a blister pack. These bits are designed for drilling through metal sheets and components and are compatible with handheld drills and drill presses. Each bit is fully ground and features a 135° point angle with chamfering adjustment to facilitate fast centre starting and reduce walking during marking and positioning.

Advantages

The bits are made entirely by precision grinding for consistent geometry and straightness. A titanium nitride coating increases wear resistance and extends tool life while improving hole surface finish. The 135° point angle with chamfering adjustment optimises cutting action for metal, reducing burr formation and enabling quicker drilling operations. Supplied as a pack of two, the set provides an immediate spare or matched pair for repetitive tasks.

Suitable for

• Drilling holes in steel sheets and light metal components
• Use with handheld electric drills and drill presses
• Maintenance, repair and repetitive metalworking tasks
• Pilot holes for fastening and assembly work

Key specifications

• Material: high-speed steel (HSS)
• Coating: titanium nitride (TiN)
• Diameter: 4.1 mm
• Overall length: 75 mm
• Point angle: 135° with chamfering adjustment
• Manufacturing: fully ground flutes and tip
• Pack quantity: 2 pieces

How to use

Secure the workpiece and select an appropriate clamping method to prevent movement. Fit the 4.1 mm Proline bit into the drill chuck and tighten securely. When drilling metal, use a suitable cutting speed and moderate feed pressure; apply cutting fluid or lubricant to improve chip evacuation and reduce heat. Start at low speed to establish the hole, then increase speed as appropriate for the material. Withdraw the bit periodically to clear chips and avoid clogging.

Usage recommendations

For best results on steel and other ferrous metals, use cutting oil and a drill press when possible. Match drill speed to material thickness and hardness: lower speeds for harder or thicker metal. Replace bits when wear becomes visible or when finish quality degrades to maintain accuracy and reduce risk of breakage.