5/16-18 x 1ft Self-Tapping Trailer Deck Screws, Type F Star Drive

In this review of the 5/16-18 x 1' self-tapping trailer deck screws, the bottom line is simple: these screws are geared toward contractors, trailer builders, and serious DIYers who need a durable, fast way to secure floorboards to both wood and thin metal. The reviewer found the biggest reason to buy is the combination of a Type F thread-forming point and a Torx T-40 star drive, which together make installation faster and reduce cam-out compared with standard Phillips or slotted screws.

Key Features

• Self-tapping Type F point: Cuts threads cleanly into wood and thin metal so you can install floorboards without pre-tapping in most trailer deck applications.
• Hardened steel construction: Provides the strength needed for heavy-duty use and resists deformation when driven at higher torque.
• Black phosphate and oil finish: Offers enhanced corrosion resistance compared with bare steel for longer life in outdoor and trailer environments.
• Flat countersunk head: Creates a flush surface when installed, improving the finished look of decking and preventing snags on cargo or feet.
• Star drive T-40: Reduces slippage and stripping so screws drive with greater control and less risk of cam-out.
• Versatile application: Suited for trailer decks, floorboard replacement, and fastening through thin plate steel into wood.

Who It's For

The screws are best for professionals and experienced DIYers who assemble trailer decks, repair floorboards, or fasten wood to thin metal where a reliable thread-cutting action is required. Contractors who need consistent performance under repeated driving will appreciate the hardened steel and Torx drive.

They are less suitable for fine woodworking or visible interior finishes where a coated stainless or decorative fastener would be preferred; also, if you need corrosion resistance for saltwater exposure, consider a purpose-made stainless fastener instead of black phosphate.

Pros & Cons

Pros

• Excellent thread-cutting performance with the Type F point for clean starts and fast installation.
• Reduced stripping and better torque transfer thanks to the T-40 star drive.
• Hardened steel and black phosphate finish provide durability and improved corrosion resistance for trailer use.

Cons

• Black phosphate is protective but not as corrosion resistant as stainless in harsh marine conditions.
• The countersunk head requires correct plate thickness and hole prep for truly flush seating in some materials.

Specifications

Size	5/16-18 x 1' (1 in)
Point Type	Type F self-tapping (thread cutting)
Drive	Star drive (Torx) T-40
Head	Flat countersunk
Material & Finish	Hardened steel, black phosphate with oil
Pack Quantity	1500 pcs

Our Verdict

These 5/16-18 x 1' Type F self-tapping screws offer a practical, cost-effective solution for trailer decks and other heavy-duty fastening tasks where speed and reliability matter. For contractors and DIYers who need strong, non-stripping drive and good thread-cutting ability, they deliver robust performance and value; choose a different material only if superior saltwater corrosion resistance is required.

Frequently Asked Questions

Can these screws cut threads in thin plate steel?
Yes, the Type F point is designed to cut threads into thin metal and customers reported successful use with 1/4 in plate steel sheets in trailer work.

Will the black phosphate finish prevent rust?
The black phosphate with oil improves corrosion resistance over bare steel for typical trailer and outdoor use, but it is not as corrosion-proof as stainless for marine exposure.

Do they strip easily during installation?
No, the Torx T-40 star drive reduces cam-out and customers say the screws rarely strip when driven with the proper driver.