Hex Bolts

Select a bolt by matching diameter, thread pitch, and length to the hole and nut or tapped thread; common specifications are listed as diameter x length (e.g., M8 x 30) or fractional inches with threads per inch (e.g., 1/4"-20). Measure the material thickness plus any washers to determine length and confirm coarse vs. fine thread based on strength and vibration requirements

For general use, zinc-plated steel offers basic corrosion resistance; stainless steel (304 or 316) resists rust better for outdoor or marine environments; alloy steel or graded bolts (e.g., Grade 8 or metric 10.9) provide higher tensile strength for structural or high-stress applications

Hex head bolts are standard for wrenching and provide good torque; flange hex heads include an integrated washer for load distribution. Choose a standard hex drive for accessibility with sockets or wrenches; consider flange or washer combinations if you need to spread load or avoid separate washers

Determine whether the application is structural or load-bearing; use bolt grade markings (e.g., Grade 5, 8, or metric 8.8, 10.9) and consult engineering specifications or load tables to match tensile and yield strength to the expected loads and safety factors

Recommended torque depends on bolt diameter, thread pitch, and grade; refer to published torque charts for dry or lubricated conditions and apply a calibrated torque wrench to reach the specified value to avoid under- or over-tightening

For critical or load-bearing joints, replace nuts and washers with equivalents because they may deform or lose clamping ability; for non-critical applications, inspect hardware for wear or thread damage before reuse

Store bolts in a dry, organized container sorted by size and grade; keep stainless or coated fasteners separate from raw steel to avoid galvanic issues, and clean threads before installation to ensure proper torque and seating