For most backyard setups, you should drill a maple tap hole about 1.5–2 inches into the wood, not counting the bark, and avoid going deeper than 2 inches.

Quick Scoop

  • Aim for 1.5–2 inches into the tree for modern 5/16" spiles, and up to about 2 inches for traditional 7/16" taps.
  • The goal is to reach the sapwood (where sap flows) without punching far into the heartwood, which doesn’t give more sap and just stresses the tree.
  • Many hobby and small producers report good results with holes around 1.5–2 inches deep; going much deeper does not increase yield and may harm the tree.

Why that depth matters

  • Sap travels in the sapwood , usually the first 1–3 inches under the bark, depending on tree size and health.
  • Too shallow: you may still be in bark or only barely into sapwood, so sap flow is weak and the spile may not hold well.
  • Too deep: once you’re past sapwood into heartwood, you don’t gain sap, and you increase internal damage and healing time.

A common guideline from maple manuals and producer discussions is “no more than 2 inches below the bark” for tap holes.

Simple rule of thumb

  1. Use a sharp, clean 5/16" or 7/16" bit.
  1. Drill at a slight upward angle to about 1.5–2 inches into solid wood (you can mark your bit with tape as a depth gauge).
  1. Stop once you’re well into bright, moist sapwood; you do not need to “bottom out” the bit.

Information gathered from public forums or data available on the internet and portrayed here.