Tap Depth & Clearance

Calculate the absolute minimum drill depth required to achieve a target thread depth. This accounts for the tap's chamfer lead and chip packing room.

TPI
Tap Configuration
Lead threads do not cut a full-form thread; they are just for starting.
Prevents the tap from "bottoming out" on its own chips and snapping.
Minimum Machining Specs
Required Drill Z-Depth
0.0000
in

Includes 0.0000 extra depth for lead and chips.

Lead Allowance
0.000 in
Chip Room
0.000 in
DFM Visualization
FULL THREAD TAP LEAD CHIPS DRILL DEPTH
The "Impossible" Thread

Designers often model threads ending at the very bottom of a hole. This is physically impossible to machine without expensive secondary operations like Thread Milling or EDM. Taps have non-functional starting threads (the lead) that must be accounted for.

Calculation Formula
Drill Depth = Target Depth + (Lead + Clearance) × Pitch
Tap Safety: If you program a tap to the very bottom of a drilled hole, the chips will compress into a solid mass. The tap will hit this "plug" and snap instantly. Always leave chip room.