Nail and Screw Pull-Out
Typical pull-out resistance by fastener and species.
Example
You enter
- Fastener type nail
- Fastener size 16d_common
- Wood species DF-L
- Penetration into receiving member (in) 1.5
You get
- Withdrawal per inch 39.5 lb/in
- Total withdrawal 59.3 lb
- Specific gravity 0.5
- Diameter (in) 0.162
Details, formula, and sources
Withdrawal capacity W = G^2.5 × D × 1380 (lb per inch of thread penetration); G is wood specific gravity, D is fastener shank diameter (NDS nail-withdrawal form). Wood screws apply an approximate 1.85× factor over common nails; lag screws are not modeled.
AWC NDS-2018 (National Design Specification for Wood Construction). Chapter 12 (dowel-type fastener withdrawal).
Free at awc.org/codes-standards.
Estimate. AHJ and licensed structural engineer govern.
Field names used by the API: fastener_type, fastener_size, species, penetration_in, withdrawal_per_inch_lb, total_withdrawal_lb, specific_gravity, diameter_in
- Specific gravity table data/construction/lumber-properties.json keyed to speciesAWC NDS-2018