Drill bit Proline 78105K — metal drill diameter 10.5 mm, length 133 mm, 1 pc

Proline 78105K is a single-piece HSS-Co metal drill bit with a cutting diameter of 10.5 mm and overall length of 133 mm, designed for precise hole making in demanding metalworking tasks. The bit features a 135° point angle with chamfering adjustment and is fully ground to ensure straightness and dimensional accuracy. Made from high-class high-speed steel with 5% cobalt, it offers improved heat resistance and wear performance for drilling into high-alloy steels, stainless steels, titanium, acid-resistant steels and cast iron, as well as other hard-to-machine materials.

Advantages

The 135° split point reduces walking at drill start and speeds up penetration, while the chamfering adjustment helps maintain accurate positioning. Full grinding produces consistent geometry and rectilinear holes. The 5% cobalt alloy increases thermal resistance and extends life when used in high-temperature, high-stress drilling conditions. Supplied individually in a blister pack, the bit is ready for use in handheld drills and drill presses.

Suitable for

• Drilling precise 10.5 mm holes in high-alloy and stainless steels
• Workshop maintenance and repair operations on metal components
• Production tasks requiring accurate through-holes in cast iron and titanium
• Use with handheld drills and drill presses for metal fabrication

Key specifications

• Cutting diameter: 10.5 mm
• Overall length: 133 mm
• Point angle: 135° with chamfering adjustment
• Material: high-speed steel with 5% cobalt (HSS-Co)
• Manufacturing: fully ground flute geometry for straightness and accuracy
• Application: suitable for high-alloy steels, stainless steels, titanium, acid-resistant steels and cast iron

How to use

Secure the drill bit in the chuck of a handheld drill or drill press, ensuring it is centered and tightened to prevent slippage. Mark the drilling position and, if needed, use a center punch to create a pilot dimple. Select an appropriate cutting speed and feed for the material being drilled; use lower speeds and steady feed when working with hard or heat-sensitive alloys. Apply cutting fluid or coolant to reduce temperature and prolong tool life. Withdraw the bit periodically to clear chips and to avoid clogging the flutes.

Usage recommendations

For best results when drilling high-alloy or stainless steels, use a steady moderate feed and apply suitable cutting fluid. Start with a pilot hole for larger diameters if precise alignment is critical. Inspect the bit for wear and replace when excessive chipping or loss of cutting performance is observed.