Dormer A777 HSCo Heavy-Duty Jobber Drill Pack of 10

The Dormer A777 Metric Cobalt Jobber Drill is designed for heavy-duty drilling tasks, including tougher metals and aerospace-grade materials, where higher heat generation is common. It features a 135° split point for precise starting and self-centering during penetration, reducing wandering and improving accuracy. The drill bit is made from HSCo cobalt steel with a bronze surface treatment to indicate the cobalt substrate and to resist built-up-edge. Its geometry includes a standard helix and thick web, optimized for demanding applications while maintaining compatibility with standard drill chucks and a range of metals.

Features

• 135° split point for self-centering
• Heavy-duty HSCo cobalt steel construction
• 5.50 mm tip diameter
• Working length 57 mm
• Overall length 93 mm
• Bronze surface treatment identifies cobalt substrate

Technical specifications

• Flute geometry: standard helix, right-hand spiral
• Thick web
• Point angles: 118° (0.30–0.95 mm); 135° 4-facet (1.00–1.40 mm); 135° split (1.50 mm and above)
• Material: HSCo cobalt steel
• Surface treatment: Bronze
• Standards: DIN 338 RN / BS 328 / ISO 235