Viking 135 Ultra Bor Super Premium H.S.S. Heavy Duty Jobbers Drill, 7/16″ Size, .4375″ Decimal Size, 4-1/16″ Flute length, 5-1/2″ Overall Length

• H.S.S. – High Speed Steel
• Designed for series 300 stainless steel, except for 303
• 2 Flutes
• Industry Standard: 240-UB
• Much tougher than cobalt steel.
• Hardness: 58 to 60 RC
• Thin web design penetrates work hardening stainless steel fast enough to continually cut beneath the chip which is hardening from deformation.
• 135 split point design stops drill walking, holds tighter hole size and takes a smaller chip resulting in less heat.
• Low temperature stress relief improves lubricity and toughness.
• Flute Shape: Standard Spiral, Helical Flute
• Cutting Direction: Right Hand
• Helix Angle: 30
• Ultra Bor Super Premium drills are made of special Hi-moly tool steel, which is much tougher than cobalt steel.
• Heavy-duty Jobbers length twist drills.
• Premium grade high-speed steel construction.
• Lower helix angle of 30 wraps slowly and is used in drilling hard materials.
• Two-flutes design with straight body shank.
• Manufactured to NAS 907B specification.
• Nitro-Carburized flute has an increased rockwell hardness.
• Rich amber color.
• 135 split point geometry (over 1.5mm).
• Workpiece Material Range: Steel, Non-Ferrous, Cast Iron, Plastics
• Country of Origin: U.S.A.

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