IMSCREWS 5/16"-18 x 4-1/2" Heavy-Duty 304 Stainless Steel Carriage Bolts (10 PCS)

Substantial Support for Deep Structural Connections
The IMSCREWS 5/16" x 4-1/2" carriage bolt is engineered for heavy-duty projects requiring deep penetration and reliable structural support. With a robust 5/16-inch diameter and an extended 4.5-inch length, these bolts are well-suited for high-load joints where stability is critical, such as through-bolting standard 4x4 posts (3.5" actual) with additional metal brackets or thick timber layers. Built for durability, they offer the stability necessary for long-term use in outdoor structures, garden gazebos, and industrial woodworking projects.

High Durability and Safety-Focused Design
Forged from premium 18-8 (304) stainless steel, these fasteners are highly resistant to rust and corrosion in coastal or humid environments. The smooth round head offers a clean appearance that reduces snagging hazards, making them an ideal choice for railings, play sets, and benches. The integrated square neck prevents rotation, allowing for easy, one-sided installation with a single wrench from the nut side.

Specifications:
- Thread: 5/16"-18 Coarse; Length: 4-1/2" (Under Head)
- Material: 304 (18-8) Stainless Steel; Full Thread

Pro-Tips:
1. Use a 5/16" drill bit to ensure a snug, structural fit for the square neck.
2. Pair with stainless steel flat washers on the nut side to distribute structural load and protect wood fibers.

Key Features

• Extra-Long Structural Reach: The 4.5-inch length is specifically engineered for through-bolting thick structural posts and multi-layer timber beams, providing the reach needed for heavy framing.
• Full-Thread Maximum Tension: Featuring a precision-cut full thread, these bolts ensure consistent clamping force and superior pull-out resistance throughout the entire deep-hole installation.
• Outdoor-Ready 304 Stainless: Forged from 18-8 (304) stainless steel to withstand harsh weather and high humidity. Ideal for ACQ pressure-treated lumber, prevent rust streaks and degradation.
• Anti-Spin Square Neck: The integrated square neck beneath the round head bites firmly into wood fibers, locking the bolt in place for effortless, one-sided installation without a second wrench.
• Smooth, Safe Finish: The domed round head provides a professional, snag-free finish without sharp edges¡ªessential for the safety of public decks, playground equipment, and outdoor furniture.

Specifications

• ASIN: B0F2FDHYZX
• Internal SKU: IMS0821
• Size: 5/16"-18 x 4-1/2"
• Material: Stainless Steel
• Finish: Stainless Steel
• Head Style: Round
• Package Quantity: 10