DIN 603 Carriage Bolts (Coach Bolts)

FULLERKREG supplies DIN 603 carriage bolts — also known as coach bolts — across all major material grades and surface treatments. The domed mushroom head and square neck beneath prevent rotation during tightening, allowing one-sided installation with a nut and washer on the reverse. Ideal for timber-to-timber, timber-to-steel, and general structural connections. Select your material and surface treatment below:

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Stainless Steel Series

Carriage Bolts (DIN 603) — Stainless Steel A2 Material: A2 / SUS304  |  Surface: Whitened & Passivated  |  Size: M6–M20

Carriage Bolts (DIN 603) — Marine Stainless Steel A4 Material: A4 / SUS316  |  Surface: Whitened & Passivated  |  Size: M6–M20

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Carbon Steel — Zinc CR3 Series

Carriage Bolts (DIN 603) — Grade 4.8 Bright Zinc CR3 Material: Carbon Steel  |  Surface: Zinc CR3 (RoHS)  |  Strength: 420 MPa  |  Size: M6–M24

Carriage Bolts (DIN 603) — Grade 8.8 Bright Zinc CR3 Material: 10B21 / 35K Steel  |  Surface: Zinc CR3 (RoHS)  |  Strength: 800 MPa  |  Size: M6–M24

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Carbon Steel — Hot Dip Galvanised (HDG) Series

Carriage Bolts (DIN 603) — Grade 4.8 Hot Dip Galvanised Material: Carbon Steel  |  Surface: Hot Dip Galvanised (HDG)  |  Strength: 420 MPa  |  Size: M6–M24

Carriage Bolts (DIN 603) — Grade 8.8 Hot Dip Galvanised Material: 10B21 / 35K Steel  |  Surface: Hot Dip Galvanised (HDG)  |  Strength: 800 MPa  |  Size: M6–M24

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Full Thread Series

Full Thread Carriage Bolts (DIN 603) — All Materials Thread: Fully threaded shank  |  Multiple materials available  |  Size: M6–M24

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Product Gallery

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About DIN 603 Carriage Bolts

• Standard: DIN 603 (Germany) ≡ ISO 8677 (International) — also known as coach bolts or cup-head bolts
• Head: Domed mushroom head — smooth, snag-free appearance on visible face
• Neck: Square neck beneath head — locks into timber or pre-punched square hole to prevent rotation
• Thread: Metric coarse, partial thread — requires nut and washer on reverse side
• Size Range: M6 – M24 (grade-dependent)
• Key Advantage: One-sided installation — no wrench needed on bolt head once square neck is seated

Can’t find the grade or size you need? Contact FULLERKREG — additional sizes and grades available on request.