Hole L:D Risk Analyzer

Evaluate the risk of tool breakage, wandering, and cost escalation based on the Length-to-Diameter (L:D) ratio of a hole.

Analysis Results
Calculated L:D Ratio
0.0
: 1
--
0
3
5
8
10+
Cost Multiplier
1.0x
Est. base machining cost
Recommended Tooling
Standard Twist Drill
Visual Proportions
Material Cross-Section
Risk Thresholds
  • < 3:1 (Optimal): Very easy. High feed rates, no pecking required in most materials.
  • 3:1 to 5:1 (Standard): Requires pecking (G83) to clear chips. Standard jobber-length drills work fine.
  • 5:1 to 8:1 (Difficult): High risk of hole wandering. Requires parabolic flute drills or coolant-through carbide.
  • > 10:1 (Extreme): Very expensive. Requires gundrilling or specialized high-pressure through-spindle coolant.
DFM Tip: If a hole is too deep, check if it can be a "through-hole" and be machined from both sides to effectively cut the L:D ratio in half!