Drill bits Proline 3 mm set, model 78030K — 3 pcs, length 61 mm

Set of three Proline metal drill bits, each 3 mm in diameter and 61 mm in length, designed for precise drilling in metal and other hard materials. Manufactured from high-class HSS steel with 5% cobalt and produced entirely by grinding, these bits deliver accurate, straight holes and high temperature resistance. The 135° point angle with chamfering adjustment enables efficient cutting and faster marking and drilling operations. Supplied in a blister pack, the set is suitable for handheld drills and drill presses used in workshop and DIY tasks such as repair, assembly and precision hole-making.

Advantages

The cobalt-alloyed HSS construction provides increased hardness and wear resistance compared with standard HSS, ensuring longer tool life when working with high-alloy and stainless steels. Fully ground flutes and tips guarantee high accuracy and rectilinearity of holes, while a 135° point angle reduces walking and improves centring on the workpiece. High temperature resistance allows sustained performance under heavy cutting conditions. The compact blister packaging keeps bits organised and protected between uses.

Suitable for

• Drilling holes in high-alloy, stainless and acid-resistant steels
• Work with titanium and creep-resisting steels
• General metalworking, repair and assembly tasks
• Use in handheld drills and drill presses for precision holes

Key specifications

• Quantity: 3 pieces
• Diameter: 3 mm
• Overall length: 61 mm
• Material: high-speed steel (HSS) with 5% cobalt
• Point angle: 135° with chamfering adjustment
• Manufacturing method: fully ground flutes and tips for high accuracy
• Suitable for high-temperature cutting and difficult-to-machine materials

How to use

Select the appropriate drill speed and clamping method for the workpiece material, secure the workpiece to prevent movement, and fit the 3 mm bit firmly in the drill chuck. For stainless, high-alloy or titanium materials, use moderate cutting speeds and apply cutting fluid to control temperature and extend bit life. Start drilling at low speed to establish a centred hole, then increase speed gradually while maintaining steady feed pressure. After drilling, retract the bit periodically to clear chips and prevent overheating.

Usage recommendations

For best results when drilling stainless and other difficult-to-machine materials, use a suitable cutting fluid, moderate speeds, and steady feed. Replace bits when wear or chipping reduces accuracy. Store the set in its blister pack to protect the ground cutting edges and maintain organisation.