Partially Threaded Hexagon Bolts (DIN 931)

FULLERKREG DIN 931 partially threaded hexagon bolts (equivalent to ISO 4014) feature a smooth unthreaded grip shank beneath the head, providing precise shear load transfer across bolted joints. Available across a comprehensive range of materials, grades, and surface finishes — from general-purpose carbon steel to marine-grade stainless and ultra-high-strength alloy steel. Select your material and grade below.

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Stainless Steel

DIN 931 — A2-70 Stainless Steel (SUS304) Material: A2 / SUS304  |  Grade: A2-70  |  Surface: Whitened & Passivated  |  Size: M6–M64

DIN 931 — A4-70 Marine Stainless Steel (SUS316) Material: A4 / SUS316  |  Grade: A4-70  |  Surface: Whitened & Passivated  |  Size: M6–M64

DIN 931 — A4-80 High Tensile Marine Stainless Steel (SUS316) Material: A4 / SUS316  |  Grade: A4-80  |  Surface: Whitened & Passivated  |  Size: M6–M36

Duplex Stainless Steel

DIN 931 — Duplex 2205 Stainless Steel (UNS S32205) Material: Duplex 2205 / 1.4462  |  PREN ≥34  |  Surface: Whitened & Passivated  |  Size: M6–M36

Carbon Steel — Zinc Plated (Zinc CR3, RoHS)

DIN 931 — Grade 8.8 Carbon Steel, Bright Zinc Plated (Zinc CR3) Material: Carbon Steel 35K  |  Grade: 8.8  |  Surface: Zinc CR3  |  Size: M6–M64

DIN 931 — Grade 10.9 Carbon Steel, Zinc Plated Material: Carbon Steel  |  Grade: 10.9  |  Surface: Zinc Plated  |  Size: M6–M36

Carbon Steel — Hot Dip Galvanised (HDG)

DIN 931 — Grade 8.8 Carbon Steel, Hot Dip Galvanised (HDG) Material: Carbon Steel 35K  |  Grade: 8.8  |  Surface: HDG 45–85μm (ISO 10684)  |  Size: M6–M64

Alloy Steel — Black Oxide

DIN 931 — Grade 8.8 Carbon Steel, Black Oxide Material: Carbon Steel  |  Grade: 8.8  |  Surface: Black Oxide  |  Size: M6–M64

DIN 931 — Grade 10.9 Alloy Steel, Black Oxide Material: Alloy Steel  |  Grade: 10.9  |  Surface: Black Oxide  |  Size: M6–M36

DIN 931 — Grade 12.9 Alloy Steel ML40Cr, Black Oxide Material: Alloy Steel ML40Cr  |  Grade: 12.9  |  Surface: Black Oxide  |  Size: M6–M36

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Quick Selection Guide

Material	Grade	Surface	Best For
A2 / SUS304	A2-70	Whitened & Passivated	General outdoor, food-grade, mild corrosive environments
A4 / SUS316	A4-70	Whitened & Passivated	Marine, coastal, chemical processing
A4 / SUS316	A4-80	Whitened & Passivated	High-load marine & chemical structural joints
Duplex 2205	—	Whitened & Passivated	Offshore, subsea, high-chloride, SCC-critical environments
Carbon Steel 35K	8.8	Zinc CR3	General industrial, automotive, indoor/mild outdoor
Carbon Steel	10.9	Zinc Plated	High-load general industrial & automotive
Carbon Steel 35K	8.8	Hot Dip Galvanised	Outdoor structural, civil engineering, 20–50+ year service life
Carbon Steel	8.8	Black Oxide	Indoor machinery, oil-wetted environments
Alloy Steel	10.9	Black Oxide	High-load precision machinery & automotive
Alloy Steel ML40Cr	12.9	Black Oxide	Ultra-high tensile — precision machinery, tooling, critical joints

Can’t find the material, grade, or size you need? Contact FULLERKREG — additional configurations available on request.