Simpson #12 x 2" Self-Drilling Hex-Washer Head Screw in 305 Stainless Steel is a precision-engineered fastener built for reliable, long-lasting connections in aluminum and fiberglass applications. Designed with a #3 drill point that eliminates the need for pre-drilling, this self-drilling screw drives cleanly into non-steel substrates and delivers a secure, corrosion-resistant hold. The indented hex-washer head provides excellent bearing surface and torque transfer, making this screw a dependable choice for professionals working with lightweight structural panels, roofing, siding, and fiberglass assemblies in demanding environments.

Key Features

• 305 Stainless Steel construction - delivers strong resistance to rust and oxidation, keeping fasteners performing reliably in wet, humid, or coastal-adjacent conditions where carbon steel screws would corrode prematurely
• Self-drilling #3 drill point - penetrates aluminum and fiberglass without pre-drilling, saving installation time and reducing the number of tools needed on the job
• Indented hex-washer head with 5/16 in. hex drive - distributes clamping load evenly across a wide bearing surface, reducing the risk of material pull-through and enabling high-torque power tool driving
• Tapping screw thread at 14 TPI - cuts its own mating thread on the first pass, forming a tight mechanical grip in aluminum and fiberglass substrates without requiring a nut or insert
• #12 screw size at 2 in. length - offers substantial holding strength for mid-depth fastening tasks, bridging layers of aluminum sheeting or fiberglass panels with confidence

Why This Product

• Purpose-built for non-steel substrates - the #3 drill point and tapping thread are specifically optimized for aluminum and fiberglass, giving you clean starts and firm threads without cracking or distorting delicate materials
• Stainless steel grade built to resist the elements - 305 stainless steel provides corrosion resistance that keeps fasteners looking and performing well in outdoor, high-moisture, and chemically exposed environments where standard zinc-plated screws fail
• One-step installation with no pre-drilling required - the self-drilling point reduces labor steps and eliminates the separate drill-and-fasten workflow, making large-scale aluminum or fiberglass fastening faster and more efficient
• Hex-washer head design for secure, professional results - the wide washer flange seats firmly against the workpiece surface, preventing over-drive and distributing load to reduce material stress or surface damage

Specifications

• Brand: Simpson Strong-Tie
• Screw Size: #12
• Length: 2 in.
• Material/Coating: Type 305 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

• S12200HDUC: 100 Pk
• S12200HDUM: 1000 Pk

Approved Applications

• Fastening aluminum panels, sheeting, and extrusions
• Securing fiberglass panels and composite assemblies
• Roofing and siding applications involving aluminum or fiberglass substrates
• Structural and finish work where corrosion resistance is required in humid or wet conditions
• Not intended for use in steel fastening applications

Frequently Asked Questions

Can this screw be used to fasten into steel?

No. This screw is specifically designed for aluminum and fiberglass applications. It is not recommended for use in steel substrates. Using it in steel may result in inadequate penetration or fastener failure.

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

No pre-drilling is required. The #3 drill point is self-drilling, meaning it bores through the material and cuts its own thread in a single step, which speeds up installation in aluminum and fiberglass.

What type of driver is needed to install this screw?

This screw uses a 5/16 in. hex drive, so a 5/16 in. hex bit driver or nut driver - compatible with most standard power drills and impact drivers - is all you need for installation.

Why is 305 stainless steel a good choice for outdoor or exposed fastening applications?

305 stainless steel offers solid resistance to rust and oxidation, making it a reliable option for environments with moisture, humidity, or chemical exposure where standard uncoated or zinc-plated fasteners would degrade over time.

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