5/16-18 x 1 3/4ft Self-Tapping Trailer Deck Screws - Durable Torx

In this review of the 5/16-18 x 1 3/4' self-tapping trailer deck screws, the bottom line is simple: these screws are built for heavy use and make trailer floor work noticeably easier. The reviewer found them best for contractors and trailer owners who need a fast, reliable fastening solution; the combination of a Type F point that cuts threads into both wood and thin metal and a Torx T-40 drive that resists cam-out is the single biggest reason to buy. The hardened steel finish and black phosphate coating also deliver peace of mind against corrosion in outdoor and marine-adjacent environments.

Key Features

• Type F point: The self-tapping tip cuts threads cleanly into wood and thin metal, reducing pre-drilling time on trailer decks and sheet attachments.
• Hardened steel construction: The robust core resists bending or breaking under high torque, making these screws suitable for heavy-duty applications.
• Black phosphate and oil coating: The finish improves corrosion resistance and helps the screws slide into material smoothly during installation.
• Torx T-40 star drive: The star drive reduces slippage and stripping, allowing higher torque transfer and more consistent seating of deck boards.
• Flat countersunk head: The head is designed to sit flush with deck boards for a neat appearance and to avoid snags once installed.

Who It's For

This product is aimed at professionals and experienced DIYers who install trailer floorboards, secure 1/4 in plate steel to frames, or need reliable fasteners for machinery and furniture assembly. Contractors who require consistent, time-saving thread forming on mixed substrates will appreciate the combination of Type F points and Torx drives.

Those who should look elsewhere include users needing stainless steel for prolonged saltwater exposure or those requiring non-countersunk head styles; if you need decorative exposed fasteners or an exact stainless alloy spec, pick a different screw type.

Pros & Cons

Pros

• Strong self-tapping Type F tip that cuts threads into both wood and thin metals with minimal pre-drilling.
• Torx T-40 drive minimizes stripping and allows higher torque during installation.
• Hardened steel with black phosphate finish offers improved durability and corrosion resistance for trailer use.

Cons

• Not stainless steel, so prolonged exposure to saltwater environments may require a different alloy.
• Flat countersunk head limits use where raised or decorative heads are desired.

Specifications

Size	5/16-18 x 1 3/4 in
Point type	Type F self-tapping (floorboard thread cutting)
Drive	Star drive Torx T-40
Head style	Flat countersunk
Material & finish	Hardened steel, black phosphate with oil coating
Pack quantity	1000 pcs

Our Verdict

These 5/16-18 x 1 3/4' self-tapping trailer deck screws are a practical choice for trailer builders and contractors who need dependable thread forming and high torque capacity. They offer good value through durable construction and reduced installation time, though buyers who require stainless fasteners for coastal exposure should choose a different material.

Frequently Asked Questions

Will these screws cut threads in thin steel?
Yes; the Type F point is designed to form threads in both wood and thin sheet metal when used with recommended plate thickness and hole size.

Do they resist stripping during installation?
The Torx T-40 star drive significantly reduces slippage and stripping compared with Phillips-style drives.

Are these stainless steel?
No; they are hardened steel with a black phosphate and oil coating, so choose stainless if you need maximum corrosion resistance in saltwater environments.