Fastener Weight Calculator

Understanding Fastener Weight

Why Fastener Weight Matters

Knowing the weight of fasteners is essential for shipping calculations, inventory management, structural load calculations, and cost estimation for large projects. Weight directly impacts shipping costs and helps in planning storage and handling requirements.

Factors Affecting Fastener Weight

• Size: Larger diameter and longer length increase weight significantly
• Material: Steel, stainless steel, brass, and titanium have different densities
• Type: Hex bolts weigh more than socket head cap screws of the same size
• Finish: Zinc plating adds minimal weight, but thick coatings can add 5-10%

Material Densities

Carbon Steel: 7.85 g/cm³ - Most common, economical, strong

Stainless Steel (304/316): 8.00 g/cm³ - Corrosion resistant, slightly heavier than carbon steel

Brass: 8.50 g/cm³ - Non-magnetic, decorative, good corrosion resistance

Aluminum: 2.70 g/cm³ - Very lightweight, 65% lighter than steel

Titanium: 4.50 g/cm³ - High strength-to-weight ratio, expensive

Approximate Weights (Steel, per 100 pieces)

M6 × 20mm bolts: ≈ 200g

M8 × 30mm bolts: ≈ 500g

M10 × 40mm bolts: ≈ 1.0kg

M12 × 50mm bolts: ≈ 1.8kg

M6 hex nuts: ≈ 50g

M8 hex nuts: ≈ 120g

M10 hex nuts: ≈ 230g

Shipping Weight Classes

• Under 500g: Standard letter post / small parcel
• 500g - 2kg: Small parcel rate
• 2kg - 10kg: Medium parcel
• 10kg - 25kg: Large parcel (one-person lift)
• Over 25kg: Heavy parcel (may require two-person handling)

Bulk Ordering Considerations

When ordering fasteners in bulk, weight impacts several factors:

• Shipping costs: Often calculated by weight zones
• Storage requirements: Heavy items need sturdy shelving
• Handling equipment: Large quantities may need forklifts or pallet jacks
• Package splitting: Orders over 30kg often split into multiple boxes

Weight Tolerance

Fastener weights have typical tolerances of ±5-10% due to manufacturing variations, coating thickness, and measurement accuracy. For precise applications, request certified weight specifications from suppliers.

Estimating Project Quantities

To estimate total project weight:

• Count required fasteners by size and type
• Calculate weight for each size/type
• Add 10-15% for spares and waste
• Consider packaging weight (boxes, bags add 5-10%)

Storage and Safety

Proper storage of bulk fasteners:

• Store heavy items on lower shelves (below waist height)
• Use weight-rated storage bins and shelving
• Label containers with contents and weight
• Never exceed shelf weight capacity
• Keep aisles clear for safe access