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DIN 980M Metal Lock Nut SS-316 A4

DIN 980M All-Metal Insert Self-Locking Nut - SUS316 A4 Stainless Steel

FULLERKREG DIN 980M A4 all-metal self-locking hex nuts are manufactured from SUS316 (A4) stainless steel with a passivated finish. SUS316 contains 2-3% molybdenum, providing significantly superior resistance to chloride-induced pitting and crevice corrosion compared to SUS304 (A2), making it the preferred choice for marine, offshore, chemical processing, and coastal environments. The metal collar insert locking mechanism generates reliable prevailing torque without any nylon component. Compliant with DIN 980M and ISO 7042 standards.

Product Overview

Parameter Details
Standard DIN 980M / ISO 7042
Type All-Metal Insert Self-Locking Hex Nut (Metal Collar Type)
Material SUS316 Stainless Steel (A4)
Grade A4-70
Surface Treatment Passivated (Bright Finish)
Thread Metric Coarse Thread (6H)
Size Range M3 to M24
Locking Mechanism Metal collar insert, no nylon, rated to 300 deg C
RoHS Compliant Yes
Brand FULLERKREG

Dimensional Data (DIN 980M)

All dimensions in millimeters (mm). Unit weight is approximate reference value based on SUS316 density 7.98 g per cm3.

Nominal Size Thread Pitch (mm) m Max (mm) Wrenching Height (mm) s Min (mm) s Max (mm) e Min (mm) Unit Weight (g/pc)
M3 0.5 3.70 1.60 5.32 5.50 6.01 approx 0.6
M4 0.7 4.20 2.70 6.78 7.00 7.66 approx 1.2
M5 0.8 5.10 3.50 7.78 8.00 8.79 approx 2.1
M6 1.0 6.00 3.70 9.78 10.00 11.05 approx 3.6
M7 1.0 7.00 4.20 10.73 11.00 12.12 approx 5.6
M8 1.25 8.00 5.40 12.73 13.00 14.38 approx 8.1
M10 1.5 10.00 6.30 15.73 16.00 18.90 approx 15
M12 1.75 12.00 8.10 17.67 18.00 21.10 approx 26
M14 2.0 14.00 9.90 21.67 22.00 24.49 approx 43
M16 2.0 16.00 11.70 23.67 24.00 26.75 approx 63
M20 2.5 20.00 13.80 29.16 30.00 32.95 approx 121
M24 3.0 24.00 16.90 35.00 36.00 39.55 approx 212

m = Total Nut Height | s = Width Across Flats | e = Width Across Corners | Unit weight values are approximate for reference only (SUS316 density 7.98 g per cm3).

Prevailing Torque Requirements (DIN 980M / ISO 7042)

Minimum and maximum prevailing torque values for A4 stainless steel DIN 980M nuts, measured on 5th engagement of standard test bolt.

Size Min Prevailing Torque (Nm) Max Prevailing Torque (Nm) Min Proof Load (kN)
M3 0.05 0.40 1.53
M4 0.10 0.70 2.78
M5 0.20 1.20 4.46
M6 0.30 2.00 6.44
M8 0.80 5.00 11.8
M10 1.20 8.00 18.7
M12 2.00 12.0 27.3
M16 4.00 25.0 50.9
M20 6.00 40.0 80.2
M24 10.0 60.0 116.0

A4 (SUS316) vs A2 (SUS304) - Why Choose A4

Property A2 / SUS304 A4 / SUS316 (This Product)
Molybdenum Content None 2-3% Mo added
Chloride Resistance Good Excellent - resists pitting and crevice corrosion
Marine Environment Suitable for mild exposure Recommended for direct seawater contact
Chemical Processing Limited acid resistance Superior resistance to acids and chlorides
Tensile Strength 700 MPa min 700 MPa min
Cost Standard Premium (Mo alloy cost)

Material and Mechanical Properties

Property Specification
Material Grade SUS316 / A4 Stainless Steel
Tensile Strength 700 MPa min
Proof Load Stress 580 MPa
Corrosion Resistance Superior - excellent resistance to chlorides, acids, and marine environments
Temperature Range -196 to +300 deg C (all-metal, no nylon insert)
Magnetic Properties Generally non-magnetic; may exhibit slight magnetism after cold working
Chemical Composition C max 0.08%, Mn max 2.0%, Si max 1.0%, Cr 16-18%, Ni 10-14%, Mo 2-3%, S max 0.03%, P max 0.045%

Selection Guide

Application Scenario Recommended Size Key Reason
Marine and Offshore Structures M6 to M24 Mo-enhanced SUS316 resists seawater pitting and crevice corrosion
Chemical and Petrochemical Plants M8 to M24 Superior resistance to acids, chlorides, and industrial chemicals
Food and Beverage Processing M3 to M16 FDA-compatible, hygienic, easy to clean, no contamination risk
Coastal and High-Humidity Environments M6 to M20 Withstands salt-laden air and condensation without surface degradation
Pharmaceutical and Medical Equipment M3 to M12 Non-toxic, corrosion-resistant, meets stringent hygiene standards

Standard Notes

  • DIN 980M specifies the metal collar insert type all-metal prevailing torque hex nut; equivalent to ISO 7042.
  • The metal collar at the top of the nut is deformed inward to create prevailing torque - no nylon or non-metallic insert used.
  • Nuts are reusable; prevailing torque remains consistent across multiple assemblies.
  • Thread tolerance: 6H per ISO 965-1.
  • Passivation treatment removes free iron and enhances corrosion resistance per ASTM A380.
  • Compatible bolt grade: A4-70 or higher recommended. Do not mix with carbon steel bolts in corrosive environments.
  • SUS316 may exhibit slight magnetic properties after cold working - this does not affect mechanical performance.
  • For seawater immersion applications, consider A4-80 grade bolts to maximize joint corrosion resistance.

Product Gallery

DIN 980M A4 SUS316 Stainless Steel All-Metal Self-Locking Nut - actual product photos:

[Photo 1] [Photo 2] [Photo 3] [Photo 4]

Why Choose FULLERKREG

Direct Manufacturer - Factory-direct pricing with full production traceability.
Strict Dimensional Control - 100% inspection against DIN 980M / ISO 7042 tolerances.
Material Certification - Mill test reports, SUS316 composition reports, and RoHS certificates available on request.
Corrosion Tested - Salt spray tested per ISO 9227; SUS316 verified for chloride resistance.
Flexible MOQ and Packaging - Bulk bags, boxes, or custom retail packaging available.
Global Shipping - FBA-ready export packaging, direct China-to-warehouse shipping.
OEM Services - Custom marking, packaging, and certification documentation supported.

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