Heavy Duty Black Timber/Log Wood Screws 6in - Strong Hold for Timbers

In this review the focus is on a full box of 6in timber screws designed for heavy timber and landscaping projects, and the bottom line is straightforward: these screws are for anyone who needs superior holding power in wood where spikes or short fasteners won't do. The review finds they deliver reliable strength and corrosion resistance for exterior use, with features aimed at easier installation and compatibility with treated lumber. For builders, landscapers, and homeowners fastening timbers or posts, the main reason to buy is the combination of length, hardened steel construction and a proven exterior coating.

Key Features

• 6in Length: Provides deep penetration for timbers and large posts, giving a much stronger mechanical hold than typical shorter wood screws.
• Hardened Heat Treated Steel: The high quality steel construction increases shear strength and reduces risk of snap during heavy load applications.
• Exterior Black Coating: A corrosion-resistant finish that passed extended salt spray testing, suitable for outdoor and coastal landscaping projects.
• ACQ Compatible: Formulated to be safe for use with ACQ treated lumber so it resists corrosion when used with modern pressure-treated wood.
• 5/16in Hex Head Drive: Uses a common hex bit size for positive torque and quick installation with standard impact drivers.
• Knurled Shoulder: Drag-reducing knurling under the head helps the screw run in cleaner and with less driving resistance, speeding installation.

Who It's For

These screws are best suited to contractors, landscapers, and DIYers who work with heavy timbers, log structures, deck subframes, or 6in posts and need a fastener that holds under shear and withdrawal forces. The full box count makes them practical for job sites where many long fasteners are required and for repeat projects where consistency matters.

They are less appropriate for fine carpentry or trim where a long, visible hex head is undesirable, and users who need shorter screws or lag bolts with different head types should look elsewhere.

Pros & Cons

Pros

• Excellent holding power compared with spikes thanks to the long threaded length and hardened steel construction.
• Durable exterior black coating that passed extensive salt spray testing for long outdoor life.
• Knurled shoulder and hex head design make installation faster and reduce drive resistance.
• ACQ compatibility avoids accelerated corrosion on pressure-treated lumber.

Cons

• The long 6in length may be overkill for some projects and received mixed feedback from a few users about suitability for every task.
• The prominent 5/16in hex head may be too visible for finish work where a countersunk or concealed fastener is preferred.

Specifications

Length	6in
Diameter	.24in
Head Height/Width	.469in
Drive	5/16in hex head bit
Material	Heat treated steel
Coating	Black exterior log screw coating (1000 hour salt spray passed)
Box Count	550 screws

Our Verdict

For anyone fastening heavy timbers, log ties, or large landscaping timbers, these 6in black timber screws are a practical, value-oriented choice thanks to their strength, corrosion resistance, and ACQ compatibility. They are not a trim fastener, but for structural wood connections and fence or post work they offer clear advantages over spikes and shorter screws.

Frequently Asked Questions

Are these screws suitable for pressure-treated lumber?
Yes. The screws are manufactured to be ACQ treated lumber compatible to resist corrosion when used with pressure-treated wood.

What driver bit do I need?
They require a 5/16in hex head bit, which fits common impact drivers and sockets for quick installation.

Will the coating hold up outdoors?
The black log screw coating passed 1000 hour salt spray testing, indicating strong corrosion resistance for exterior use.