Twist drill

A twist drill, comprising:

• an elongated round bar formed about a longitudinal central axis;
• helical flutes formed within said bar and generated about said central axis;
• lands formed between said flutes;
• a point at one end of said bar;
• a shank end at a remaining end of said bar;
• wherein said point includes:
• cutting shoulders formed along said lands on the periphery of said bar;
• cutting lips formed along continuous smooth curved lines leading transversely toward said central axis directly from said cutting shoulders;
• a central chisel point at the inward ends of said cutting lips and centered on said central axis;
• wherein said cutting shoulders are spaced axially toward said shank end from said chisel point;
• wherein said cutting lips are longitudinally concave with bases thereof spaced axially toward said shank end from said cutting shoulders;
• heel surfaces formed at said point, leading from said cutting lips about said axis to trailing edges defined by said flutes;
• rearward shoulders along said trailing edges that are axially spaced toward said shank end from the bases of said cutting lips, inwardly to said chisel point;
• and
• chisel edge forming surfaces adjacent to said heel surfaces and angularly offset toward the shank end therefrom, leading inwardly from the lands to said chisel point, thereby forming two straight chisel edges at said chisel point diverging from the central axis and joining the concave cutting lips at points equally spaced from the central axis.