Precise Left Hand H.S.S Jobbers Length Twist Drill, 1/4″ Size, .2500″ Decimal Diameter, 4″ Overall Length

• H.S.S. – High Speed Steel
• Hardness: 58 to 60 RC
• No. of Flutes: 2
• For most general purpose drilling operations.
• Although appropriate for a wide range of normal ferrous and non-ferrous materials, the drills are commonly preferred for machining non-ferrous and non-metallic materials and alloys, including aluminum, magnesium, zinc, brass, bronze and other non-ferrous materials and alloys.
• The left hand helix requires that these drills be used for screw machines, portable or stationary machine tools or hand held manual drills with a counter-clockwise spindle rotation.
• This helix design is also useful for applications where the chips must eject in a direction opposite from normal.
• For optimal performance and the best tool life, suitable lubricating/cutting oils or the appropriate coolant fluids are recommended.
• Left hand (counter-clockwise rotation) cutting direction.
• Standard two flute design with opposite helix direction.
• Standard spiral, helical flutes.
• Straight shanks that correspond to the drill diameter.
• Jobbers length that corresponds to the drill diameter.
• The jobbers length used for each of these drills is variable and is determined by the specific drill diameter, offering the best balance between overall drill rigidity and depth capacity for each drill diameter.
• Precision ground flutes.
• Cylindrically ground.
• General purpose drills for counter-clockwise spindle rotation.
• 118 point angle and standard web thickness.
• Series: A11
• Workpiece Material Range: Steel, Cast Iron, Plastics

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