"IMSCREWS 3/8 x 4 Heavy-Duty Lag Bolts - 304 Stainless Steel (5 pcs)

Elite Strength for Massive Structural Timber
When projects demand extra-deep penetration and unyielding shear resistance, these 3/8 diameter x 4 bolts deliver. Engineered for heavy timber framing, securing large gate posts, and mounting structural steel to 6x6 beams. The 4-inch length provides maximum stability for the thickest load-bearing wood members.

Vise-Like Clamping with Partial Threading
Our partially threaded shank is critical for long fasteners. It allows the bolt to spin freely in the outer board while the deep threads bite into the support post. This draws the timber members together into a gap-free joint, eliminating the bridging effect where thick boards remain loose—a common failure in extra-long full-thread screws.

304 Stainless Exterior Defense
Forged from premium 18-8 (304) Stainless Steel for ultimate weather resistance. compatible with ACQ pressure-treated lumber. It prevents chemical corrosion and eliminates unsightly rust streaks on high-value cedar, redwood, or deck framing.

Technical FAQ
¡ñ Tools Required: Fits a standard 9/16 hex socket or wrench.
¡ñ Pre-drilling: Mandatory for this diameter. Use a 1/4 bit for softwoods or 9/32 bit for hardwoods to prevent splitting.
¡ñ Why 4 length? Optimized for passing through 2 or 2.5 thick timber with a deep 1.5 + thread anchor in the base post.
¡ñ Resilience: Rated for marine, coastal, and high-humidity outdoor use.

Specifications:
- Size: 3/8 x 4
- Thread: Partially Threaded (Max Clamping)
- Material: 304 Stainless Steel (18-8)
- Drive: 9/16 Hex Head
- Qty: 5 pcs"

Key Features

• ELITE CLAMPING POWER The partially threaded design ensures the smooth shank passes through the outer member, pulling heavy timber pieces together with immense force for a gap-free joint.
• INDUSTRIAL STRUCTURAL HOLD The robust 3/8-inch diameter and 4-inch length provide elite shear resistance for heavy-duty framing, 4x4 posts, and deck main beams.
• 304 EXTERIOR DEFENSE Forged from premium 304 (18-8) stainless steel to prevent rust and staining in cedar, redwood, or ACQ pressure-treated lumber projects.
• STABLE TORQUE DRIVE Features a precision hex head for 9/16 power sockets, providing stable torque transfer for controlled, slip-free seating in dense timber cores.
• TECHNICAL SPECIFICATION To prevent splitting from this robust 3/8 bolt, pre-drilling a pilot hole (1/4 for softwoods, 9/32 for hardwoods) is mandatory for structural safety.

Specifications

• ASIN: B0F21C32N8
• Internal SKU: IMS0679
• Size: 3/8" x 4"
• Material: Stainless Steel
• Finish: Stainless Steel
• Head Style: Hex
• Package Quantity: 5