What size wood screw do I need?

For most woodworking use #8 screws - they are the most versatile size. For light work like trim and small boxes use #6. For heavy structural work use #10 or #12. The screw should penetrate at least two-thirds of its total length into the receiving piece - for 3/4 inch material that means a 2 inch screw minimum.

Do I need a pilot hole for wood screws?

Always pilot drill in hardwood and near edges in any wood. In hardwood like oak or maple skip the pilot hole and the wood will split. In softwood pilot drill within 1 inch of any edge and for screws #10 and larger. Small screws #6 and under in the middle of softwood panels generally do not need a pilot hole.

What is the difference between a pilot hole and a clearance hole?

A pilot hole is drilled in the receiving piece and is smaller than the screw thread so threads grip the wood. A clearance hole is drilled in the top piece and is larger than the screw shank so the screw slides through freely. Without a clearance hole the screw lifts the top piece instead of clamping the two pieces together.

What drive type is best for wood screws?

Star or Torx drive is the best choice for any application with torque - deck screws, structural work, cabinet assembly. It eliminates cam-out under load. Square Robertson drive is excellent and standard in Canada. Phillips is the most common but strips easily under high torque. Avoid slotted drive for power driving.

What wood screw gauge should I use for cabinets?

Use #8 washer-head screws with T20 star drive for cabinet face frame assembly. Fine thread grips dense hardwood better than coarse thread. Length should be 2 to 2-1/2 inches for standard 3/4 inch cabinet material. Always pilot drill hardwood face frames to prevent splitting.

Wood Screw Size Chart: Complete Guide to Types, Gauges & Lengths (2026)

Wood screw sizing is confusing because gauge numbers run backwards from what you expect — a #14 screw is larger than a #6. This guide covers everything: gauge to diameter conversion, correct lengths, pilot hole sizes, and which type to use for every application.

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The Screw Size Selector gives you the exact gauge, length, pilot hole, and coating for any wood project — free, instant, no signup.

Wood Screw Gauge to Diameter Chart

Gauge	Shank Diameter	Pilot Hole (Softwood)	Pilot Hole (Hardwood)	Clearance Hole
#4	0.112"	3/64"	1/16"	1/8"
#6	0.138"	5/64"	3/32"	9/64"
#8	0.164"	7/64"	1/8"	11/64"
#10	0.190"	9/64"	9/64"	3/16"
#12	0.216"	5/32"	11/64"	7/32"
#14	0.242"	11/64"	3/16"	1/4"

Wood Screw Length Guide

The rule of thumb: the screw should penetrate at least two-thirds of its total length into the receiving piece. For a 2 inch screw through 3/4 inch material, that means 1-1/4 inch of penetration — acceptable. For structural applications use three-quarters penetration.

Top Material	Min Screw Length	Recommended
1/2" plywood	1-1/4"	1-1/2" to 2"
3/4" board	1-1/2"	2" to 2-1/2"
1-1/2" (2x lumber)	2-1/2"	3" to 3-1/2"
Face frame to cabinet box	1-1/4"	1-5/8" to 2"

Head Types Explained

Flat head (countersunk): Sits flush with or below the surface. Use for furniture, cabinets, and any application where a flush finish is needed.
Pan head: Low rounded head that sits proud of the surface. Use where flush finish is not required — hinges, hardware, electrical boxes.
Oval head: Partially countersunk with a decorative dome above. Used for visible fastening on trim and hardware.
Bugle head: Self-countersinks without a washer. Standard for drywall and decking.
Washer head: Large bearing surface distributes load. Use for cabinet face frames and applications needing high clamping force.

Drive Types: Which to Use

Star / Torx (T20, T25): Best overall. No cam-out under load. Use for decking, framing, structural work.
Square (Robertson): Standard in Canada. Excellent cam-out resistance. T-handle drivers are common on job sites.
Phillips: Most common but prone to cam-out. Fine for light work, problematic for driving long screws.
Slotted: Avoid for power driving. Only for hand work on very light applications.

Where to Buy

Canada:

Home Depot CA → RONA → Home Hardware → Amazon CA →

United States:

Home Depot US → Lowe's → Ace Hardware → Amazon US →

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Related Guides

Deck Screws Complete Guide — Outdoor screw selection
Screw Coating Guide — Which coating for outdoor use
Structural Screws vs Lag Bolts — For framing connections
Pilot Hole Size Chart for Screws — Every gauge, every material
Screw Size Selector — Get your exact screw spec instantly