Fastener Withdrawal/Shear Strength Reference

Load ratings and strength values for common fasteners in various materials. Essential for structural and load-bearing applications.

Understanding Fastener Strength

Withdrawal Strength: Resistance to being pulled straight out (parallel to fastener)

Shear Strength: Resistance to sideways force (perpendicular to fastener)

Note: Values shown are for standard SPF (Spruce-Pine-Fir) lumber. Hardwoods may require pilot holes but provide better holding. All values are approximate and for reference only - consult structural engineer for load-bearing applications.

Common Nails - Holding Power in SPF Lumber
Nail Type & SizeLengthWithdrawal (lbs)Shear (lbs)Typical Use
16d Common3.5"80135Framing, structural
10d Common3"60110Framing, general
8d Common2.5"4590Sheathing, siding
6d Common2"3570Light framing, trim
16d Box (thinner)3.5"70105Finish work, less splitting
8d Finish2.5"3560Trim, molding
Wood Screws - Holding Power in SPF Lumber
Screw Type & SizeLengthWithdrawal (lbs)Shear (lbs)Typical Use
#10 x 3" Wood Screw3"220210Structural connections
#10 x 3" Deck Screw3"200195Decking, outdoor
#8 x 2.5" Wood Screw2.5"175165General construction
#8 x 2" Deck Screw2"1401355/4 decking, fence
#6 x 1.5" Drywall Screw1.5"9080Drywall, light duty
#8 x 1.25" Cabinet Screw1.25"110105Cabinets, furniture

Screws provide 2-3x better withdrawal strength than nails of similar diameter

Construction Screws - Heavy-Duty Fasteners

GRK & Similar Structural Screws:

SizeWithdrawal (lbs)Shear (lbs)Use
#10 x 3"280245Ledger boards, joist hangers
#10 x 5"450245Beam connections, heavy duty
1/4" x 6" Lag Screw500+600Major structural connections

Advantages: No pre-drilling required (most cases), star drive resists cam-out, hardened steel, weather resistant coatings

Factors Affecting Holding Power

Wood Species

  • Softwoods (Pine, Fir): Baseline values shown in charts
  • Hardwoods (Oak, Maple): 1.5-2x better holding, but may require pilot holes
  • Very soft woods (Cedar): 20-30% less holding power

Moisture Content

  • Green (wet) lumber: Reduced holding power initially
  • As wood dries, fasteners may loosen slightly
  • Kiln-dried lumber provides most consistent results

Grain Direction

  • Perpendicular to grain: Best withdrawal strength
  • Parallel to grain: 20-40% less withdrawal, risk of splitting
  • End grain: 50% or less holding power

Penetration Depth

  • Minimum 1.5" penetration into receiving member for structural
  • Deeper penetration = better holding (within reason)
  • At least 6x fastener diameter for good holding
Nails vs. Screws: When to Use Each

Use Nails When:

  • Shear strength matters most: Framing walls, floors
  • Speed is important: Nail guns much faster
  • Flexibility needed: Nails allow slight movement (good for framing)
  • Building code specifies: Many codes require nails for certain applications
  • Cost matters: Nails generally cheaper per fastener

Use Screws When:

  • Withdrawal strength critical: Ledger boards, deck railings
  • May need to disassemble: Screws easier to remove
  • Working alone: No helper to hold pieces together
  • Preventing squeaks: Subfloors, stairs (better grip)
  • Outdoor projects: Better corrosion resistance available
  • Finish work: More control, no hammer marks
Safety Factors & Structural Applications

⚠️ IMPORTANT: Do not use these values for critical structural calculations

  • Values shown are ultimate strength, not safe working loads
  • Engineers apply safety factors of 3-5x for structural designs
  • Multiple fasteners: Don't simply add values - consult span tables
  • Dynamic loads (swings, moving objects): Higher safety factors needed
  • Always follow local building codes for structural fastening

For Structural Projects:

  • Consult building code fastener schedules
  • Use engineer-approved plans for load-bearing elements
  • Follow manufacturer specifications for joist hangers, connectors
  • Building inspectors verify proper fastening
Common Fastening Applications

Wall Framing (stud to plate): Two 16d common nails or 3" structural screws

Joist to Rim Board: Three 16d nails toenailed OR joist hanger with specified nails

Subfloor (3/4" plywood): 8d ring shank nails or #8 x 2" screws, 6" edges, 12" field

Deck Boards: Two #8 x 2.5" deck screws per joist

Deck Ledger (critical!): 1/2" lag screws or structural screws, per code spacing

Fence Pickets: Two 8d galvanized nails or #8 x 2" screws per rail

Drywall (1/2"): #6 x 1-1/4" drywall screws, 12" on center

Trim/Molding: 6d or 8d finish nails or 1-1/2" 18ga brad nails

Specialty Fasteners

Ring Shank / Spiral Nails

Holding Power: 40-60% better withdrawal than smooth nails

Use: Subfloors, sheathing, any high-withdrawal application

Joist Hanger Nails

Critical: Use only manufacturer-specified nails (usually 10d x 1.5" specific type)

Do NOT substitute: Regular nails, drywall screws, or random fasteners

Structural Connectors (Simpson, etc.)

Follow specs: Each connector has specific fastener requirements

Load tables: Based on using correct fasteners - substitution voids rating

Additional Information

About This Fastener Strength Guide

This comprehensive fastener withdrawal and shear strength reference helps DIYers and builders select the right nails and screws for their projects based on actual holding power. Understanding fastener strength is essential for structural integrity, preventing failures, and building to code requirements.

Withdrawal strength measures resistance to being pulled straight out, while shear strength measures resistance to sideways forces. Screws typically provide 2-3x better withdrawal strength than nails of similar size, but nails excel in shear strength and are often specified by building codes for framing applications.

This guide covers common nails and screws, factors affecting holding power (wood species, grain direction, moisture content), when to choose nails vs screws, and proper fastener selection for common applications from framing to deck building.

Why Use This Fastener Strength Reference Guide?

Selecting the right fastener ensures your projects are structurally sound and meet building codes. This guide helps you choose appropriate fasteners for any application.

  • Compare withdrawal and shear strength of common nails and screws
  • Understand how wood species and grain direction affect holding power
  • Know when to use nails vs screws for optimal performance
  • Select correct fasteners for specific applications like framing, decking, and drywall
  • Recognize safety factors needed for structural calculations
  • Follow proper specifications for joist hangers and structural connectors
Frequently Asked Questions

Free Fastener Strength Chart - Simple Withdrawal & Shear Guide | DIYProject.ai