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Metric Reference/DIN 934 / ISO 4032
Metric Reference

DIN 934 / ISO 4032

Metric Hex Nuts, Standard Pattern
CategoryNut Specification · Metric · Dimensional
Typical pairingISO 898-1 / DIN 931 bolts (matching material class); ISO 7089 flat washers
IndustriesManufacturing, automotive, machinery, European and Asian OEM, anywhere drawings are dimensioned in metric
Applies toM1.6 – M64 standard-pattern hex nuts (height ≈ 0.8 × nominal diameter)
DIN 934 (now ISO 4032) is the dimensional standard for the everyday metric hex nut in sizes M1.6 through M64. Like DIN 931 for bolts, it defines geometry only — width across flats, height, tolerances. It does not specify material; pair with ISO 898-2 (carbon / alloy) or ISO 3506-2 (stainless) for the mechanical properties.

Scope

DIN 934 was adopted as ISO 4032 with the same dimensional rules — most current drawings reference one or the other interchangeably. The standard covers metric hex nuts in sizes M1.6 through M64 in product grades A and B (Grade A for smaller / tighter-tolerance applications; Grade B is the loose industrial pattern).

The "standard pattern" designation means the nut height is approximately 0.8 × nominal diameter (e.g. M16 nut height ≈ 13 mm). For applications needing greater thread engagement, use:

  • DIN 6334 / ISO 4033 — high (heavy) hex nut, height ≈ 1.0 × diameter
  • DIN 985 — nylon-insert lock nut (for vibration resistance)
  • DIN 6925 / ISO 7042 — all-metal prevailing-torque lock nut

How to read the callout

ISO 4032 - M16 - 8 - HDG

This decodes as:

  • ISO 4032 — DIN 934 / ISO 4032 standard hex nut
  • M16 — 16 mm nominal diameter (coarse pitch unless explicitly fine)
  • 8 — ISO 898-2 nut property class 8 (matched to bolt class 8.8 or lower)
  • HDG — hot-dip galvanized

The nut property class is a single number (not the X.Y format used on bolts) — it specifies the proof load capability. Class 8 nuts can develop the full proof load of property class 8.8 bolts; class 10 nuts match 10.9 bolts.

Bolt-to-nut matching

Bolt classRecommended nut classNotes
4.8, 5.8Class 5Carbon steel low-strength
8.8Class 8The most common pairing — galvanized or plain
10.9Class 10Higher-strength alloy steel
12.9Class 12Specialty; often a heavy-pattern (DIN 6334) nut
Stainless A2-70Stainless A2-70 nutMatch the alloy and grade
Stainless A4-80Stainless A4-80 nutMatch the alloy and grade

Mismatched pairings (e.g. class 5 nut on a 10.9 bolt) reduce joint strength to the lower of the two — a common field error in mixed metric inventories.

Common sizes stocked

We stock DIN 934 standard hex nuts in M3 through M30 in property classes 8 (galvanized and plain) and 10. Stainless is available in A2-70 and A4-70/80 in most popular sizes.

For sizes above M30, expect a 1–3 week lead time depending on alloy and finish.

  • ISO 898-2 — Mechanical properties for carbon and alloy steel nuts (the material spec to pair with DIN 934)
  • ISO 3506-2 — Mechanical properties for stainless steel nuts
  • DIN 931 / ISO 4014 — Matching metric hex head bolt
  • DIN 6334 / ISO 4033 — Heavy (high) metric hex nut for higher-strength pairings
Cross-references
DIN 931 / ISO 4014Matching metric hex head bolt
← PreviousDIN 931 / ISO 4014Next →—
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