These 3/8"-16 x 4" (4.0") long Grade 8 (G8) Bolts are engineered for applications where strength, reliability, and vibration resistance matter most. Each pack combines a high-strength Grade 8 (G8) hex bolt, a matching nylon locking hex nut, one flat washer for load distribution. Designed for use in automotive repairs, trailer builds, agricultural equipment, shop machinery, and structural assemblies, this kit eliminates the need to source parts separately—saving time while ensuring proper fit and performance. Whether you're a professional mechanic, fabricator, or serious DIYer, this fastener kit delivers the confidence of industrial-grade hardware in a convenient, ready-to-use package.