Viking Drill and Tool St. Paul MN
America's Finest High-Speed Steel Cutting Tools™
Proudly Manufactured in the USA
                             with globally sourced material

Viking Drill and Tool — Drill Troubleshooting

Drill bits are cutting tools used to create cylindrical holes, almost always of circular cross-section. Drill bits come in many sizes and have many uses. Bits are usually connected to a mechanism, often simply referred to as a drill, which rotates them and provides torque and axial force to create the hole.

Broken Drill Bits

Cause:

    1. Flutes clogged with chips, drill binds in hole (Common in deep holes)
    2. Drill binding due to worn outer corners
    3. Work insecurely held
    4. Excessive feed
    5. Improper point
    6. Twist drill is dull

Correction:

  • Use a drill with wider flutes and/ or faster helix angle
  • Consider polished flutes
  • Withdraw drill at regular intervals to clear chips
  • If chips are not broken up, consider heavier feeds OR a chip breaker design.
  • Repoint or replace drill bit
  • Check for excessive speed, inadequate or incorrect coolant, excessive run out as drill enters work material
  • Use adequate holding or clamping devices
  • Reduce feed
  • Check for correct lip clearance
  • Use proper type of drill and point for the application
  • Replace before dulling occurs. Check Feeds, Speeds, and No. 5 for premature dulling

Broken Tang

Cause:

    1. Shank or Socke damaged
    2. Twist Drill not properly seated in socket

Correction:

  • Repair OR Replace
  • Check for positive, secure fit

Chips Not Breaking Up

Cause:

    1. Insufficient feed
    2. Improper style of drill and/or point

Correction:

  • Increase feed

Damaged Point

Cause:

    1. Using hard object to tap drill into socket
    2. Dropping, Mishandling drill bit

Correction:

  • Use soft lead, plastic, etc. hammer
  • Handle with care

Over-sized Hole

Cause:

    1. Drill point off center
    2. Machine spindle not rigid OR Not running true
    3. Work piece loose and/ or vibrating

Correction:

  • Repoint accurately OR Replace with properly pointed drill
  • Repair if possible; consider use of bushing
  • Tighten and hold securely

Rough Hole

Cause:

    1. Incorrect point grind and/or dull drill
    2. Excessive feed
    3. Incorrect or Insufficient coolant

Correction:

  • Repoint or replace with properly pointed drill
  • Reduce feed
  • Correct and Adjust

Poor Tool Life

Cause:

    1. Coolant not reaching drill point or insufficient or incorrect coolant
    2. Speed too high and/or feed too low
    3. Wrong type of point and/or drill for application

Correction:

  • Correct and Adjust
  • Review and Adjust
  • Review requirements and conditions

Web Splits

Cause:

    1. Insufficient lip clearance
    2. Point thinned too much
    3. Excessive feed

Correction:

  • Repoint OR Replace with properly pointed drill
  • Repoint OR Replace with properly pointed drill
  • Reduce feed

Chipped Lips

Cause:

    1. Excessive lip clearance and/ or heel relief

Correction:

  • Repoint or replace with properly pointed drill

Cutting Edge Chipping
Cutting Edge Chipping Diagram

Cause:

    1. Large run out after attached to machine, loose holder
    2. Cutting speeds or feeds is too high

    Correction:

    • Check holder and/or select another holder
    • Reduce cutting Speeds OR Feeds

Broken Outer Corners

Cause:

    1. Insufficient or incorrect coolant
    2. Excessive speed
    3. Scale, Hard spots encountered in material

Correction:

  • Correct and Adjust
  • Reduce speed
  • No final remedy. If this condition is prevalent; lower feeds and speeds may help