IMSCREWS 3/8"-16 x 4" Heavy-Duty 304 Stainless Steel Carriage Bolts (5 PCS)

Substantial Strength for 4x4 Posts and Heavy Timber Construction
The IMSCREWS 3/8" x 4" carriage bolt is engineered for structural projects requiring reliable penetration through thick materials. With a robust 3/8-inch diameter and an extended 4-inch length, these bolts are the ideal choice for securing standard 4x4 timber posts (actual 3.5" thickness). They provide the necessary length to fully cross the post while leaving sufficient thread to accommodate structural washers and hex nuts for a snug, permanent connection. Built for longevity, they offer the structural stability required for outdoor pergolas, heavy-duty fencing, and residential deck framing.

Superior Durability and Safety-Focused Design
Forged from premium 18-8 (304) stainless steel, these fasteners offer superior resistance to rust and corrosion, even when exposed to harsh coastal or humid environments. The smooth round head creates a clean, tamper-resistant look that reduces snagging hazards, making them a safe choice for high-traffic areas like playground equipment, benches, and residential decks. The integrated square neck prevents the bolt from spinning during installation, allowing for easy, one-sided fastening with a single wrench from the nut side.

Specifications:
Thread Size: 3/8"-16 Coarse (UNC); Length: 4" (Measured from Under Head); Material: 304 (18-8) Stainless Steel; Full Thread

Pro-Tips:
1. Use a 3/8" drill bit to ensure a snug, structural fit for the square neck.
2. Pair with 304 SS flat washers and hex nuts to distribute heavy structural loads and protect wood fibers.

Key Features

• Extra-Long 4 Reach: Specifically sized for full penetration of standard 4x4 posts (3.5 actual) or joining multiple heavy timber beams.
• Heavy-Duty 3/8 Shank: The reinforced 3/8-inch diameter offers industrial-grade shear strength for critical structural joints in decks and pergolas.
• Weather-Resistant 304 SS: Forged from 18-8 (304) stainless steel, offering high resistance to rust in coastal air and with treated lumber.
• Smooth Safety Head: The drive-free round head design provides a professional finish and helps prevent snags on clothing or skin.
• Anti-Spin Square Neck: The precision square shoulder locks into wood fibers to prevent rotation, enabling efficient one-sided installation.

Specifications

• ASIN: B0F2F71DXD
• Internal SKU: IMS0862
• Size: 3/8"-16 x 4"
• Material: Stainless Steel
• Finish: Stainless Steel
• Head Style: Round
• Package Quantity: 5