About This

• Complete 4-packs: Includes 4 Grade 8 hex bolts, 4 hardened flat washers, 4 Grade 8 nylon lock nuts— everything you need for strong, vibration-resistant fastening in one convenient pack. Bolts 3/8" x 4.0" long. Nuts and washers fit 3/8" bolts.
• Grade 8 Strength for Demanding Jobs: High-tensile SAE J429 Grade 8 bolts and nuts deliver superior load capacity and shear strength, making this kit ideal for automotive, trailer, machinery, and structural applications. All washers are hardened, which is compatible with a Grade 8 fastening system. Threads are made to the requirements of ASME B1.1. ASME B18.2.1 Dimensional Requirements. SAE J429 Material and Strength Level. ASTM A564 Material and Strength Level. ASTM F788 Surface Discontinuities. ASME B18.18 Inspection and Quality Assurance.
• Utimate Anti-Vibration Nylon Locking System: washers help prevent loosening under torque, shock, and movement — perfect for equipment that sees constant vibration or cyclic loads.
• Precision-Matched Components: All fasteners are 3/8"-16 UNC for reliable fit and consistent clamping force across every assembly — no mismatched hardware, no guesswork.
• Built for Pros & Serious DIYers: Whether you’re repairing equipment, building fixtures, or assembling heavy components, this kit delivers industrial-grade reliability in a compact, easy-to-store format.

Overview

• Material : Alloy Steel
• Thread Size : 3/8"-16
• Exterior Finish : Yellow Zinc
• Manufacturer Grade : Grade 8
• Head Style : Hex