Simpson #12 x 2" Self-Drilling Hex-Washer Head Screw in 316 Stainless Steel is engineered for reliable fastening in demanding environments where corrosion resistance is non-negotiable. Designed specifically for use with aluminum and fiberglass materials, this self-drilling screw eliminates the need for a pre-drilled pilot hole, saving time on the job and reducing the number of tools required. The 316 stainless steel construction offers superior resistance to saltwater, moisture, and harsh outdoor conditions - making it a trusted choice for marine, coastal, and industrial applications where standard fasteners would quickly degrade.

Key Features

• 316 Stainless Steel construction - delivers exceptional resistance to corrosion, rust, and chemical exposure, ensuring long-term holding power even in saltwater or high-humidity environments
• #3 drill point (self-drilling tip) - penetrates aluminum and fiberglass without pre-drilling, speeding up installation and reducing labor requirements
• Indented hex-washer head with 5/16 in. hex drive - provides a large bearing surface for a secure, tight connection while allowing high torque with a standard hex driver or socket
• Tapping screw thread at 14 TPI - forms its own mating thread in the base material, eliminating the need for separate nuts and creating a strong, vibration-resistant hold
• #12 screw size at 2" length - sized for medium-duty fastening applications through aluminum panels, fiberglass sections, and similar materials requiring a robust, durable connection

Why This Product

• Specifically formulated for aluminum and fiberglass fastening - 316 stainless steel avoids galvanic corrosion issues that would occur with carbon steel or lower-grade stainless fasteners in contact with aluminum
• The self-drilling tip combined with tapping threads means one fastener does two jobs - drilling and threading - reducing installation steps and improving overall project efficiency
• The hex-washer head design distributes clamping force across a wider area than a standard hex head, reducing the risk of pull-through in thinner or softer base materials like fiberglass
• 316 grade stainless steel is widely recognized for use in marine and coastal construction - making this screw a dependable choice for boat docks, outdoor enclosures, and other wet or salt-air environments

Specifications

• Brand: Simpson Strong-Tie
• Screw Size: #12
• Length: 2 in.
• Material: Type 316 Stainless Steel
• Head Type: Hex Washer Head (Indented)
• Drive Type: 5/16 in. Hex
• Thread Type: Tapping Threads
• TPI: 14
• Point Type: #3 Drill Point
• Country of Origin: Taiwan

Available Pack Options

• T12200HDUC: 100 Pk
• T12200HDUM: 1000 Pk

Approved Applications

• Fastening aluminum panels, frames, and extrusions
• Securing fiberglass sections, panels, and enclosures
• Marine and coastal construction environments requiring corrosion-resistant fasteners
• Outdoor applications subject to moisture, humidity, or salt air
• Note: Not intended for fastening into steel substrates.

Frequently Asked Questions

Can this screw be used to fasten into steel?

No. This screw is designed specifically for aluminum and fiberglass fastening applications. It is not recommended for use in steel substrates. Using it in steel could result in inadequate holding power or premature failure.

Why is 316 stainless steel preferred over 304 stainless for outdoor and marine use?

316 stainless steel contains added molybdenum, which significantly improves its resistance to chloride corrosion - the type of corrosion most commonly caused by saltwater and coastal air. This makes 316 stainless fasteners a stronger choice for marine, waterfront, and high-humidity environments compared to standard 304 stainless steel.

Do I need to pre-drill a hole before installing this screw?

No. This screw features a #3 drill point, which allows it to drill its own pilot hole as it is driven into aluminum or fiberglass. This self-drilling capability eliminates the need for a separate drilling step, simplifying installation.

What tool is needed to drive this screw?

This screw uses a 5/16 in. hex drive, compatible with a standard hex driver bit, nut driver, or socket. A power drill or impact driver fitted with the appropriate bit is recommended for efficient installation.

Note: Product dimensions and/or thread length may differ from picture. Please see the item description above for specifications.