1/4-20 x 1 Flat Head Floorboard Screws, Type F (Six-Lobe), Black Phosphate vs 5/16-18 x 3 1/2" self-tapping trailer deck screws, flat head, Type F, T-40 star drive

Overall winner: 5/16-18 x 3 1/2" self-tapping trailer deck screws, flat head, Type F, T-40 star drive

Key Differences

Pick A (5/16-18 x 3.5" self-tapping trailer deck screws) if you want a lower listed price tier and hardened-steel, rust-resistant fastener for heavy trailer/deck use. Pick B (1/4-20 x 1 flat head floorboard screws) if you need a flush countersunk head and six-lobe drive for finish floorboard or wood-floor fastening where a low-profile head and oil finish matter

1/4-20 x 1 Flat Head Floorboard Screws, Type F (Six-Lobe), Black Phosphate

1/4-20 x 1 Flat Head Floorboard Screws, Type F (Six-Lobe), Black Phosphate

Newport Fasteners • ★ 4.2/5 • Mid-Range

Floorboard screws for installing wood floors into truck trailers. Six-lobe flat heads provide a flush countersunk surface. Oil finish offers rust inhibition and lubrication; self tapping thread cutting for secure fastening

Pros

  • six-lobe recess for drive stability
  • flush countersunk head for smooth surface
  • oil finish acts as rust inhibitor and lubricant
  • self-tapping thread cutting for installation ease

Cons

  • mixed signals on self-drilling capability
  • customer notes on drill accuracy variability
Check current price on Amazon →
5/16-18 x 3 1/2" self-tapping trailer deck screws, flat head, Type F, T-40 star drive

5/16-18 x 3 1/2" self-tapping trailer deck screws, flat head, Type F, T-40 star drive

Newport Fasteners • ★ 4.2/5 • Mid-Range

Self-tapping screws designed for wood and metal deck installations. Hardened steel with black phosphate and oil coating for corrosion resistance; Type F point for efficient thread cutting. Customer insight notes easy installation and durable performance, with positive feedback on quality and value

Pros

  • self-tapping with Type F point
  • works with wood and metal
  • hardened steel with rust resistance
  • ease of installation

Cons

  • mixed confirmation on self-drilling capability
Check current price on Amazon →

Head-to-Head

CriteriaWinner
Price Newport Fasteners
Durability Newport Fasteners
Versatility Newport Fasteners
User Reviews Tie