Hex Bolt Weight Chart: Sizes in mm to Kg 

The procurement manager, structural estimator, freight coordinator, or anyone who must prepare bill of quantities and calculate shipping needs using accurate figures should have a satisfying and accurate hex bolt weight chart. Most of the reference charts published, however, combine partial-thread hex bolts and fully threaded hex screws into a single unlabeled reference chart without reference to the dimensional standards.

Two nominally the same size and length hex fasteners won’t weigh the same because one is only partially threaded and the other is fully threaded, with the shank diameter being the same between the two. This guide contains a verified metric and imperial hex bolt size chart which is clearly marked for DIN 931 / ISO 4014 (partial thread), DIN 933 / ISO 4017 (full thread) and ASME B18.2.1 standards. All values are determined by exact volumetric formulas and are validated per piece, per 100 pieces and per 1,000 pieces.

Hex Bolt vs Hex Screw: Why the Standard Matters

When consulting a standard hex bolt weight chart, the underlying standard dictates the volume of metal in the fastener. The primary distinction centers on thread coverage along the shaft:

• DIN 931 / ISO 4014 (Partial Thread): These feature an unthreaded smooth shank under the head before the thread begins. Because the smooth unthreaded shank retains the full nominal major diameter, it contains more material volume.
• DIN 933 / ISO 4017 (Full Thread): These are fully threaded right up to the underside of the hex head. The continuous threading removes metal down to the pitch and root diameters along the entire shaft length.

At short lengths (such as M6 x 10 mm or M8 x 15 mm), both standards are fully threaded by necessity. However, at medium to long lengths, a DIN 931 partial thread bolt weighs noticeably more than a DIN 933 full thread screw of identical nominal size.

For full technical specifications on unthreaded shank lengths and thread engagement boundaries, refer to our comprehensive guide on ISO 4014 partial thread specifications. To cross-reference dimensional standards, view our dedicated summaries for DIN standards, ISO standards, and ASME standards.

How Hex Bolt Weight Is Calculated

Calculating the theoretical weight of a hex bolt involves breaking the fastener down into two geometric solids: the hexagonal head and the cylindrical shaft.

Mathematical Formula

Total Weight = (Volumeₕₑₐd + Volumeₛₕₐft) × Density

1. Volume of the Hexagonal Head (Vₕ)

The volume of a regular hexagonal head is calculated from its width across flats (s) and head height (k):

Vh=32×s2×k≈0.866025×s2×k

2. Volume of the Shaft (Vₛ)

• For fully threaded screws (DIN 933 / ISO 4017):

Vs=π4×(d2)2×L

(where d2 is the effective stress diameter / root diameter, and L is nominal length)

• For partial-thread bolts (DIN 931 / ISO 4014):

Vs=[π4×d22×(L−b)]+[π4×(d2)2×b]

(where d is nominal diameter, b is thread length, and L−b is unthreaded shank length)

Standard Hex Bolt Dimension Specifications (Imperial)

Hex Bolt Weight per Piece (by Diameter & Length)

Hex Bolt Weight Chart – Metric Dimensions & Weight (MM & KG) 

DIN 933 Hex Screw Weight Chart 

Frequently Asked Questions