Drill Bit Size Chart
Tools
Data 2026.07.13-audit.1
Checking connection

Pilot hole · traditional wood screws only

Ask about the joint
before naming the bit.

A screw number alone is not enough. This advisor first separates withdrawal from lateral loading, then applies the AWC rule to seven public, checked traditional wood-screw rows. Modern proprietary screws stop at the manufacturer boundary.

Traditional wood-screw lead-hole advisor AWC NDS 2018 §12.1.5 · B18.6.1 SCOPE
Primary loading direction

Use the project species/design value, not a hardness guess. The boundaries at 0.50 and 0.60 change the cited installation rule.

AWC rule applied #8 · withdrawal · G 0.55

Threaded-member lead-hole target

0.0917 in
2.329 mm

70% of the traditional screw root diameter for withdrawal loading.

Closest fractional bit 3/32 +0.052 mm
Side-member hole Not specified here withdrawal rule
Source dimensions Root 0.131 in Shank 0.164 in

Nearest listed nominal diameters · comparison only

2.3 mm 2.3 mm#42 2.375 mm3/32 2.381 mm

Section B · two-member joint

One screw can require two hole diameters.

In lateral loading, the unthreaded shank passes through the side member while the thread develops purchase in the main member. The labels update with the rule above; the drawing is schematic, not a drilling-depth prescription.

Traditional wood screw through two boards A section drawing separates the side-member shank zone from the main-member threaded zone. SIDE MEMBER · NOT SPECIFIED WITHDRAWAL RULE THREADED MEMBER 0.0917 IN SIDE MEMBER MAIN MEMBER

Audited launch subset

Traditional dimensions used.

These are nominal shank and root diameters from AWC Appendix L, Table L3. They are not substitutes for measuring an unidentified screw or reading a proprietary screw box.

Traditional ANSI/ASME B18.6.1 wood-screw rows exposed in this release
ScrewShank diameterRoot diameterStatus
#6 0.138 in 0.113 in AWC Table L3
#7 0.151 in 0.122 in AWC Table L3
#8 0.164 in 0.131 in AWC Table L3
#9 0.177 in 0.142 in AWC Table L3
#10 0.190 in 0.152 in AWC Table L3
#12 0.216 in 0.171 in AWC Table L3
#14 0.242 in 0.196 in AWC Table L3

Installation rule

AWC NDS §12.1.5.

The ratios shown by the advisor come from the 2018 NDS Chapter 12 installation provisions for wood screws meeting ANSI/ASME B18.6.1.

Open Chapter 12 PDF

Hard stop

Not a structural design check.

Pilot diameter does not establish allowable withdrawal, lateral capacity, edge distance, embedment, splitting resistance, or code compliance. Qualified design and the exact fastener instructions still govern.

Read method and limits