About

Structural engineers and procurement officers often face the challenge of estimating the shipping weight of thousands of small fasteners. While a single bolt is negligible, a pallet of M24 assemblies is a significant logistical load. This specialized engineering calculator eliminates the need for manual weighing or catalogue lookups. It utilizes an embedded database of standard steel densities and DIN/ISO geometric specifications to derive the theoretical weight of bolts, nuts, and washers. This is crucial for calculating shipping costs, checking against maximum safe working loads (SWL) for cranes, or verifying supplier delivery notes.

Formulas

The calculator uses a volume-based approach multiplied by the density of steel (ρ ≈ 7.85 g/cm³). For a bolt, the weight W is approximated as:

W = V_head + V_shank × ρ

Where V_shank is derived from the nominal diameter area (πr²) and length. The tool applies correction factors for thread removal and head geometry specific to the selected DIN standard.

Reference Data

Standard	Description	Typical Application
DIN 931	Hexagon Head Bolt (Part Thread)	General structural fastening where grip length is required.
DIN 933	Hexagon Head Bolt (Full Thread)	Universal fastening, machine assembly.
DIN 912	Socket Head Cap Screw (Allen)	High-tensile applications, recessed mounting.
DIN 934	Hexagon Nut (Standard)	Mating with standard metric bolts.
DIN 125	Flat Washer (Form A)	Load distribution under bolt heads/nuts.
DIN 127	Spring Lock Washer	Vibration resistance.

Frequently Asked Questions

The calculations use a standard density of 7.85 g/cm³ which is accurate for carbon steel. Stainless steel (Series 300) has a density of approx 7.9-8.0 g/cm³, resulting in a weight difference of less than 2%. For general logistics, this difference is usually negligible.

Nuts and washers have standardized thicknesses defined by their DIN/ISO specification relative to their diameter. Length is only a variable parameter for bolts and screws.

No. The output represents the bare steel weight. Heavy hot-dip galvanizing can add 3-5% to the weight, but standard zinc plating is negligible.

The database covers the most common coarse thread metric sizes (M3 to M36) and standard lengths. Fine thread variations or custom non-standard lengths are not currently supported.