Screws vs Nails: Which Fastener for Structural Work
Nails vs screws for framing and structural connections — shear vs withdrawal behavior, code-required uses, sizes, and when each fastener wins.
Updated August 20, 2026
The oldest argument in carpentry has a physics answer: a nail is a smooth ductile pin that excels in shear and yields gracefully, while a screw is a threaded anchor that excels in withdrawal and fails suddenly. Framing codes are written around the first behavior, decking and cabinet work around the second — and most fastener mistakes come from asking one to do the other’s job.
The size systems encode the split. Nails run on the penny scale — a 16d common is 3-1/2 in long on a 0.162 in shank, the stick the IRC fastening schedule assumes — while wood screws run on a gauge whose major diameter follows the ASME B18.6.1 formula (a #8 is 0.164 in). Between the ordinary wood screw and the nail now sits a third category, the load-rated structural screw, which carries manufacturer ICC-ES values and has quietly taken over ledgers and hold-down repairs.
Every dimension in the table below is mapped from the same FPL/NDS-adjudicated constants behind this site’s nail and screw size chart, so the comparison and the chart cannot drift apart; the judgment rows then say what those numbers mean at the joint.
Side by Side
| Spec | Nails | Screws (structural use) |
|---|---|---|
| Load behaviorAWC NDS Chapter 12 treats both as dowel-type fasteners; the ductility difference is why diaphragm and shear-wall tables specify nails. | Ductile in shear — bends and redistributes load before letting go; weak in withdrawal (smooth shank backs out) | Strong in withdrawal — threads mechanically lock the wood; hardened shanks are stiffer in shear but fail with little warning |
| Common structural sizes | 16d common: 3-1/2 in × 0.162 in; 10d common: 3 in × 0.148 in | Wood screws by gauge: #8 = 0.164 in, #10 = 0.190 in major diameter; structural screws are sized per their evaluation report |
| Pilot-hole practice | None — driven directly; blunting the point reduces splitting in brittle stock | Wood screws: #8 pilots 7/64″ softwood / 1/8″ hardwood, #10 pilots 1/8″ softwood / 9/64″ hardwood; structural screws self-drill per their report |
| Code-prescribed uses | The IRC Table R602.3(1) fastening schedule and every diaphragm/shear-wall nailing table are written in nails — substituting screws there requires engineering, not preference | No generic prescriptive role; specific listed screws are named in ledger, lateral-load, and hold-down details via their evaluation reports |
| Structural-screw category | Not applicable — commodity nails are covered by the code tables themselves | Engineered, load-rated screws (ledger, timber, hold-down types) with published ICC-ES shear and withdrawal values; a different product class from deck and drywall screws |
| Installation speed & tooling | Fastest by far with a framing nailer; hammer-drivable anywhere, no battery required | Slower per fastener even with an impact driver; big structural screws want a high-torque driver and patience |
| Removability & adjustment | Destructive to remove — pry bars, cat’s paws, and dented lumber | Backs out clean and re-drives; the disassembly and squeak-fix fastener |
Which One for the Job
Wall framing and structural sheathing
Nails
The prescriptive fastening schedule and the shear-wall nailing tables are nail tables — a screw substitution walks out of the code’s deemed-to-comply path and forfeits the ductile yielding those lateral values assume. Hardened screws in a sheathing edge can snap in the same event a nail rides out bent.
Deck ledger connection to the house
Screws (structural use)
A ledger dies by pulling away from the rim, which is a withdrawal-and-tension problem — exactly what nails are worst at and what listed ledger screws and lag screws publish values for. The IRC ledger table itself is written in lag screws and bolts, with proprietary structural screws qualifying through their evaluation reports; smooth-shank nails have no place in this joint.
Squeak-free subfloor installation
Screws (structural use)
Floor squeaks are fasteners letting sheathing lift off the joist and rub — a withdrawal failure in slow motion. Threads plus construction adhesive keep the panel clamped for the life of the floor, and a screwed panel comes back up intact when a plumber needs the bay. Ring-shank nails are the production compromise; smooth nails are how the squeak got there.
Joist hangers and framing connectors
Nails
Connector load tables are tested and published with the maker’s specified hanger nails filling every round hole. Ordinary screws — including deck screws — are brittle in the shear-and-cycling regime a hanger sees and void the listed values; the only screws permitted are the connector manufacturer’s own listed structural screws where the catalog explicitly says so.
Frequently Asked Questions
Why do framing codes insist on nails instead of screws?
Because the lateral design values behind the fastening schedule assume a ductile dowel that bends and keeps carrying load. A common nail yields and redistributes force during wind or seismic racking; a hardened screw of similar size is stiffer until it snaps, and case-hardened deck screws snap early. Screws enter structural work through specific tested products with published values, not as a field substitution for the nailing schedule.
Are structural screws the same thing as deck screws?
No — they are separate product classes that happen to share a drive style. Structural screws are load-rated fasteners with ICC-ES evaluation reports publishing shear, withdrawal, and head pull-through values, heat-treated to stay ductile. Deck screws are corrosion-coated wood screws with no structural listing; using them in a ledger, hanger, or hold-down puts an unrated part in a rated joint.
When does a wood screw actually need a pilot hole?
Whenever the wood can split or the screw can snap — dense hardwoods, ends of boards, and any gauge from about #8 up in hard stock. The consensus chart sizes step with density: a #8 takes a 7/64-inch pilot in softwood but 1/8-inch in hardwood, because dense fibers push back instead of compressing. Modern structural screws are the exception, with self-drilling tips qualified in their evaluation reports.
Do screws hold more than nails?
In withdrawal, overwhelmingly — threads engage the wood mechanically while a smooth shank relies on friction that creep and moisture cycling erode. In shear, size for size, the comparison flips toward the nail’s ductility. That is the whole selection rule in one sentence: load trying to slide the joint favors nails; load trying to pull it apart favors screws.
Try the Calculators
Sources
- ANSI/AWC NDS Chapter 12 — dowel-type fastener design values (nails, wood screws, lag screws)
- IRC Table R602.3(1) fastening schedule and the deck-ledger fastening table (lag screws/bolts) — prescriptive fastener assignments
- FPL Wood Handbook, Ch. 8 (Fastenings) — withdrawal and lateral behavior of nails and wood screws; pilot/lead-hole guidance
- Category-level ICC-ES evaluation reports for proprietary structural screws (published shear/withdrawal values; self-drilling qualification), via the nail-screw-sizes chart’s adjudicated constants for all dimensions