ISO 4032 Hexagon Regular Nuts | Dimensions & Specifications

Standard Overview

What Is ISO 4032?

The international standard for hexagon regular nuts used across construction, machinery, automotive, and structural applications worldwide.

ISO 4032 specifies the characteristics of hexagon regular nuts, Style 1, in steel and stainless steel, with metric coarse pitch threads from M1.6 to M64 and product grades A and B. It is the current international standard that has superseded the legacy German DIN 934 standard.

Product Grade A

Tighter Tolerances

Applies to threads M1.6 to M24 and nominal lengths ≤ 10d or 150 mm (whichever is shorter). Used in precision machinery, automotive, and critical assemblies where dimensional accuracy matters.

Product Grade B

Standard Tolerances

Applies to threads over M24 or nominal lengths over 10d or 150 mm. Suitable for general construction, structural steel, and heavy engineering where standard tolerances are acceptable.

                        Key Takeaway: ISO 4032 defines the dimensional family for metric hexagon regular nuts, but it does not define strength grade. Always specify the property class (e.g., Class 8, 10, or 12) from ISO 898-2, and material/coating separately for a complete RFQ.
                    

Technical Specifications

Standard Specifications

Size Range & Thread Details

Thread range: M1.6 up to and including M64
Thread type: Metric coarse pitch per ISO 261 (no pitch specification required — all ISO 4032 nuts are coarse thread)
Style: Style 1 — standard height hexagon regular nut
For fine pitch threads: Refer to ISO 8673 (hexagon regular nuts, fine pitch)

Mechanical Properties & Materials

Carbon Steel Property Classes (ISO 898-2): 04, 05, 5, 6, 8, 10, 12
Stainless Steel Grades (ISO 3506-2): A2-50, A2-70, A4-50, A4-70, A4-80
Coatings: Zinc plated (blue/white/yellow Cr3+), hot-dip galvanized (ISO 10684), zinc flake (Geomet/Dacromet), PTFE, and plain (self-colour)
Marking: Property class and manufacturer identifier stamped on the nut face
Thread tolerance: 6H as standard

ISO 4032 vs DIN 934 — Key Differences

While DIN 934 and ISO 4032 are often treated as interchangeable in general procurement, they are not automatically identical. Before substituting one for the other, verify these critical dimensions:

Feature	DIN 934	ISO 4032
Standard Origin	German (legacy)	International (active)
Nut Height (≤M4)	Same	Same
Nut Height (>M4)	Slightly lower	Slightly higher
WAF M10 / M12 / M14	17 / 19 / 22 mm	16 / 18 / 21 mm
WAF M22	32 mm	34 mm
Pitch Spec.	Required	Not required (all coarse)
Mech. Standard	DIN 267-4	ISO 898-2

Engineering warning: A nut may thread onto the bolt but still fail assembly if the socket cannot reach the flats in a recessed pocket, or if the nut height changes the clamp stack. Always confirm drawing dimensions before substituting DIN 934 with ISO 4032.

Dimension Tables

ISO 4032 Key Dimensions (Style 1)

Dimensions in millimetres for common coarse-thread sizes. s = Width Across Flats, e = Width Across Corners, m = Nut Height.

Size	Pitch	s (max)	s (min)	e (min)	m (max)	m (min)
M5	0.8	8.00	7.78	8.79	4.70	4.40
M6	1.0	10.00	9.78	11.05	5.20	4.90
M8	1.25	13.00	12.73	14.38	6.80	6.44
M10	1.5	16.00	15.73	17.77	8.40	8.04
M12	1.75	18.00	17.73	20.03	10.80	10.37
M16	2.0	24.00	23.67	26.75	14.80	14.10
M20	2.5	30.00	29.16	32.95	18.00	16.90
M24	3.0	36.00	35.00	39.55	21.50	20.20
M30	3.5	46.00	45.00	50.85	25.60	24.30
M36	4.0	55.00	53.80	60.79	31.00	29.40

                    Thread tolerance: ISO 4032 nuts are supplied with 6H thread tolerance as standard. For coated nuts, thread fit must be verified after coating with go/no-go gauges. Hot-dip galvanized nuts may require tapping after galvanizing to restore thread fit.
                

Application Guidance

Bolt-Nut Compatibility & Best Practice

Match Property Classes

Always pair nuts with bolts of compatible strength. A Class 10 nut should be used with a 10.9 bolt. Using a low-grade nut on a high-strength bolt can cause thread stripping before target preload is reached.

Coastal UAE Projects

For outdoor and marine environments in the UAE, specify A4-316 stainless steel or hot-dip galvanized ISO 4032 nuts. HDG nuts typically require re-tapping after coating to maintain 6H thread fit.

Complete RFQ Format

A strong RFQ reads: "ISO 4032 M12 × 1.75 Class 8 hex nut, carbon steel, zinc plated Cr3+, thread tolerance 6H, with material certificate and go/no-go gauge inspection."

Related Standards

Complementary ISO Nut & Bolt Standards

Standard	Description	Grade / Style
ISO 4033	Hexagon high nuts (Style 2)	Product Grades A & B
ISO 4034	Hexagon nuts — General purpose	Product Grade C
ISO 4035	Hexagon thin nuts (chamfered)	Product Grades A & B
ISO 4036	Hexagon thin nuts (unchamfered)	Product Grade B
ISO 8673	Hexagon regular nuts — Metric fine pitch	Product Grades A & B
ISO 8674	Hexagon high nuts — Metric fine pitch	Product Grades A & B
ISO 898-2	Mechanical properties of steel nuts	Property Classes 04–12
ISO 3506-2	Mechanical properties of stainless steel nuts	A2-50 to A4-80
ISO 4014 / 4017	Hexagon head bolts (mating bolts)	Product Grades A & B
ASTM A563	Carbon & alloy steel nuts (inch series)	Grades A, B, C, D, DH

FAQ

Frequently Asked Questions

Is ISO 4032 the same as DIN 934?

No. While they are closely related metric hex nut standards, ISO 4032 nuts are slightly taller than DIN 934 for sizes above M4, and WAF differs at M10, M12, M14, and M22. Always verify drawing dimensions before substituting.

Does ISO 4032 define nut strength?

No — ISO 4032 defines dimensional characteristics only. Strength grades (Class 5, 8, 10, 12) must be specified separately from ISO 898-2 for steel nuts, or ISO 3506-2 for stainless steel nuts.

What is the difference between Style 1 and Style 2 nuts?

Style 1 (ISO 4032) is the standard-height hexagon regular nut. Style 2 (ISO 4033) is a higher nut with greater load-bearing capacity, typically used with high-strength bolts where more thread engagement is required.

Can I use ISO 4032 nuts with fine pitch bolts?

No — ISO 4032 covers metric coarse pitch threads only. For fine pitch metric threads, use ISO 8673 (regular height) or ISO 8674 (high nuts).

What nut class should I use with a Grade 8.8 bolt?

Use a Class 8 nut with an 8.8 bolt, or Class 10 for higher safety margins. Never use a Class 5 or 6 nut with an 8.8 bolt — the nut threads may strip before the bolt reaches preload.

How does hot-dip galvanizing affect ISO 4032 nuts?

HDG adds significant thickness to threads. Nuts are typically tapped oversize before galvanizing or re-tapped after coating to restore 6H thread fit. Always verify thread gauge acceptance after coating.

Need ISO 4032 Hex Nuts in UAE?

We stock ISO 4032 hexagon regular nuts in Class 5 through Class 12, carbon steel and stainless steel, with zinc plating, HDG, and plain finishes. Same-day dispatch from RAK FREEZONE across UAE & GCC.

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