Timber Screw Usage Chart

Fastener type	Wood-to-wood fastening	Lag bolt replacement	Decks and ledgers	Marine/coastal
SDWS, Oversize washer	✓		✓
SDWH, Hex washer	✓		✓
SDWH, Hex washer HDG	✓	✓	✓	✓
SDWH, SS Hex washer	✓		✓	✓