Screw Size Chart& Pilot Hole Reference Guide

The professional standard for avoiding split wood and broken heads. Compare #4 to #14 Wood Screws, Machine Screws, and Metric sizes. Get the exact drill bit size for Softwood vs Hardwood pilot holes.

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Gauge Matrix#0 to #24 sizes
Pilot InfoSoft vs Hardwood
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Woodwork Wood (#0-#24)

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Wood Screw Size Chart

Pilot Hole Recommendations for Softwood & HardwoodA4

SizeMajor DiaPilot (Soft)Pilot (Hard)
#00.060"1/64"1/32"
#10.073"1/32"3/64"
#20.086"3/64"1/16"
#30.099"1/16"5/64"
#40.112"1/16"3/32"
#50.125"5/64"3/32"
#60.138"5/64"1/8"
#70.151"3/32"1/8"
#80.164"3/32"1/8"
#90.177"7/64"9/64"
#100.190"7/64"5/32"
#120.216"1/8"11/64"
#140.242"9/64"3/16"
#160.268"5/32"13/64"
#180.294"3/16"7/32"
#200.320"13/64"1/4"
#240.372"1/4"9/32"

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File Details

Sizes

17

Type

Wood (#0-#24)

0KB

300 DPI

Quick Gauge to MM Reference

Screw GaugeDecimal (Inch)Metric (mm)Common Pilot Bit
#40.112"2.84mm1/16" or 5/64"
#60.138"3.51mm5/64" or 3/32"
#80.164"4.17mm3/32" or 1/8"
#100.190"4.83mm7/64" or 9/64"
#120.216"5.49mm1/8" or 5/32"

How to Select the Right Pilot Hole

Proper drilling prevents wood failure and ensures maximum holding power.

Check Material Density

Softwoods (Pine, Cedar) need smaller pilot holes. Hardwoods (Oak, Maple) need holes closer to the shank diameter.

Identify Gauge (#)

Find the screw gauge on the packaging. If unknown, measure the major thread diameter with calipers.

Drill Shank Clearance

When joining two boards, the top board should have a clearance hole so the screw pulls it tight against the base board.

Drive Systems & Torque Efficiency

Why your choice of screw head matters as much as the size.

Phillips (+)

The standard for decades. Designed to 'cam out' (slip) to prevent over-tightening.

Slotted (-)

Traditional look. Difficult to drive with power tools without slipping.

Torx / Star

The modern pro choice. Zero cam-out and maximum torque transfer. T25 is standard.

Robertson

Square drive. Extremely popular in Canada and deck building for stability.

Application Guide

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Cabinetry & Furniture

Precision work in expensive hardwoods. Use the Hardwood Pilot column to avoid hairline fractures in face frames.

  • Countersinking for flush finish
  • Pocket hole screw alternatives
  • #6 & #8 standard cabinet sizes
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Decking & Framing

High-load applications where Robertson or Torx drives are essential to avoid bit slipping and stripping.

  • Stainless steel for outdoors
  • Lag screws for structural posts
  • Self-drilling tips vs pilot holes
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Machine & Repair

Precision machine screws (uniform diameter) require exact clearance holes for tight fitment in pre-tapped holes.

  • Metric M3, M4, M5 standards
  • Close vs Free fit tolerance
  • Vibration resistance tips

Screw Systems Decoded

Wood Screw Gauge (#)

An old system where #0 is small and #24 is large. It relates to the outer diameter of the threads. Always use a pilot hole to make room for the core shank.

Metric (M)

The simplest system. M followed by millimeters (e.g. M5 = 5mm diameter). Metric screws are increasingly common in US flat-pack furniture.

Related Workshop References

Complete your garage reference wall with these printable guides.

Frequently Asked Questions

What is the diameter of a #8 screw?
A #8 wood or machine screw has a major thread diameter of 0.164 inches (approximately 4.17mm). It is one of the most common sizes for general woodworking.
Why do I need a larger pilot hole for hardwood?
Hardwoods like oak and maple don't compress. If the pilot hole is too small, the friction can snap the screw head off or split the wood fibers. Softwoods like pine are more forgiving and can take a smaller hole for more grip.
What size drill bit for a #10 wood screw?
For a #10 wood screw, use a 7/64" drill bit for softwood or a 9/64" bit for hardwood. If you are drilling a clearance hole (top board), use 3/16".
Is M5 the same as #10 screw?
They are very close! M5 is 5mm (0.197"), while #10 is 0.190" (4.83mm). While they aren't perfectly interchangeable in tapped holes, they are often swapped in wood projects.
What does T25 mean on a screw box?
T25 refers to the Torx (Star) drive size. You will need a T25 star bit to drive these screws. It's the most common size for high-quality construction screws.
What is a 'cam-out'?
Cam-out is when the screwdriver bit slips out of the screw head under torque. It is common with Phillips heads but almost non-existent with Torx or Robertson drives.