Thin Hexagon Nuts (DIN 439) — Zinc Plated Low Carbon Steel (Grade 4)

FULLERKREG DIN 439 thin hexagon nuts in low carbon steel with trivalent zinc plating (Zinc Cr3) offer a cost-effective, RoHS-compliant solution for general industrial locking and jam-nut applications. Manufactured to DIN 439 / ISO 4035 standards with a reduced height profile, these Grade 4 jam nuts are the most economical choice for high-volume assemblies in automotive, construction, machinery, and general manufacturing where moderate corrosion protection is sufficient. The trivalent chromate (Cr3) zinc coating provides a bright, uniform finish while meeting modern environmental compliance requirements.

Product Specifications

Attribute	Details
Standard	DIN 439 / ISO 4035
Type	Thin Hexagon Nut (Jam Nut / Half Nut)
Material	Low Carbon Steel (C ≤ 0.25%)
Strength Grade	Grade 4 (per ISO 4035 / DIN 439)
Surface Treatment	Zinc Plated, Trivalent Chromate Cr3 (RoHS Compliant)
Coating Thickness	5 – 8 μm (typical)
Salt Spray Resistance	≥ 72 hours (per ISO 9227)
Size Range	M3 – M48
Thread	Metric Coarse Thread (per ISO 261)
RoHS Compliant	Yes — Trivalent Cr3 (no hexavalent chromium Cr6)

Dimensional Data (DIN 439 / ISO 4035) — All dimensions in mm

Width Across Flats (s), Width Across Corners (e), Nut Height (m) — per DIN 439B standard. Unit weight (g) is theoretical reference for low carbon steel (density 7.85 g/cm³), excluding plating.

Thread Size	Pitch (mm)	s max (mm)	s min (mm)	e min (mm)	m max (mm)	m min (mm)	Unit Weight (g/pc)
M3	0.5	5.50	5.30	6.01	1.80	1.55	0.34
M3.5	0.6	6.00	5.80	6.01	2.00	1.75	0.43
M4	0.7	7.00	6.78	7.66	2.20	1.95	0.71
M5	0.8	8.00	7.78	8.79	2.70	2.45	1.16
M6	1	10.00	9.78	11.05	2.70	2.45	1.75
M8	1.25	13.00	12.73	14.38	4.00	3.70	3.79
M10	1.5	17.00	16.73	18.90	5.00	4.70	7.08
M10×1.25	1.25	17.00	16.73	18.90	5.00	4.70	7.08
M12	1.75	19.00	18.67	21.10	6.00	5.70	11.60
M12×1.25	1.25	19.00	18.67	21.10	6.00	5.70	11.60
M14	2	22.00	21.67	24.49	7.00	6.42	18.20
M16	2	24.00	23.67	26.75	8.00	7.42	26.35
M18	2.5	27.00	26.16	29.56	9.00	8.42	36.90
M20	2.5	30.00	29.16	32.95	10.00	9.10	51.10
M22	2.5	32.00	31.00	35.03	11.00	9.90	66.80
M24	3	36.00	35.00	39.55	12.00	10.90	96.30
M27	3	41.00	40.00	45.20	13.50	12.40	142.50
M30	3.5	46.00	45.00	50.85	15.00	13.90	201.50
M33	3.5	50.00	49.00	55.37	16.50	15.40	273.00
M36	4	55.00	53.80	60.79	18.00	16.90	373.00
M39	4	60.00	58.80	66.44	19.50	18.20	481.00
M42	4.5	65.00	63.10	71.30	21.00	19.70	614.00
M45	4.5	70.00	68.10	76.95	22.50	21.20	776.00
M48	5	75.00	73.10	82.60	24.00	22.70	961.00

* Unit weight values are theoretical reference based on low carbon steel density (7.85 g/cm³), excluding zinc plating weight. Actual weights may vary slightly. M3.5, M45 are non-preferred sizes; availability limited and MOQ may be higher.

Mechanical Properties — Grade 4 (per ISO 4035 / DIN 439)

Property	Value
Proof Load Stress	380 N/mm² (M5–M16) / 330 N/mm² (M16–M39)
Hardness (Vickers)	HV 110 – 250
Hardness (Rockwell)	HRB 67 – HRC 24
Material	Low carbon steel, C ≤ 0.25%, S ≤ 0.060%, P ≤ 0.060%
Density	7.85 g/cm³

Zinc Plating Specification — Cr3 Trivalent Chromate

Parameter	Specification
Plating Type	Electrolytic Zinc + Trivalent Chromate Passivation (Cr3)
Chromate Type	Trivalent (Cr³⁺) — No hexavalent chromium (Cr⁶⁺)
Coating Thickness	5 – 8 μm (per ISO 4042)
Appearance	Bright silver / blue-white finish
Salt Spray Resistance	≥ 72 hours to white rust (per ISO 9227)
RoHS Compliance	Yes — compliant with EU RoHS Directive 2011/65/EU
REACH Compliance	Yes — no SVHC substances above threshold
Standard Reference	ISO 4042, ISO 9227, ASTM B633

Surface Finish Comparison — Why Zinc Cr3?

Property	Zinc Cr3 (This Product)	Zinc Cr6 (Legacy)	Hot-Dip Galvanized
RoHS Compliant	✓ Yes	✗ No (Cr6 banned)	✓ Yes
Coating Thickness	5–8 μm	5–8 μm	45–100 μm
Thread Fit After Plating	Excellent (thin coat)	Excellent	May require re-tapping
Salt Spray (white rust)	≥ 72 hrs	≥ 96 hrs	≥ 500 hrs
Appearance	Bright silver-blue	Bright silver-yellow	Matte grey
Cost	Low	Low	Higher

Selection Guide

Application	Recommended Size	Notes
General machinery & equipment	M6 – M24	Most economical choice for indoor / sheltered environments
Automotive assembly	M6 – M16	RoHS Cr3 required for EU automotive supply chains
Construction & structural	M12 – M48	Locking / jam nut for large-diameter bolted connections
Locking / Jam applications	M3 – M48	Pair with standard hex nut; tighten jam nut first
Electronics & appliances	M3 – M8	RoHS Cr3 compliant for consumer electronics applications
High-volume OEM supply	All sizes	Contact FULLERKREG for bulk pricing, custom packaging & labeling

Standard Reference

These thin hexagon nuts conform to DIN 439 Part B (equivalent to ISO 4035), Grade 4. Zinc plating conforms to ISO 4042 and salt spray testing per ISO 9227. Thread tolerance is per ISO 965-2 (6H).

• DIN 439B — Hexagon thin nuts, chamfered, metric coarse and fine pitch thread
• ISO 4035 — Hexagon thin nuts (unchamfered) — equivalent international standard
• ISO 4042 — Fasteners — Electroplated coating systems
• ISO 9227 — Corrosion tests in artificial atmospheres — Salt spray tests
• ISO 965-2 — Thread tolerance class 6H
• EU RoHS 2011/65/EU — Restriction of hazardous substances (Cr6 free)

Product Gallery

DIN 439 Thin Hexagon Nuts — Zinc Plated Low Carbon Steel Grade 4 — FULLERKREG

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Why Choose FULLERKREG?

🏭 Direct Manufacturer — Factory-direct pricing with no middlemen, ensuring competitive wholesale rates.
✅ Genuine Cr3 Zinc Plating — Verified trivalent chromate; no Cr6 substitution; full RoHS compliance documentation available.
📐 Precision to Standard — Every nut manufactured and inspected to DIN 439 / ISO 4035 dimensional tolerances.
📄 Full Compliance Docs — RoHS declaration, REACH statement, and material certificates available on request.
📦 Bulk & Wholesale Ready — Flexible MOQ, bulk packaging, and custom labeling available for distributors and OEMs.
🚢 Global Shipping — Reliable international logistics with experience in B2B export to 50+ countries.
🔧 Wide Size Range — M3 to M48 in stock; the broadest DIN 439 carbon steel range for one-stop sourcing.