Metric Property Class 4.6
Class 4.6 is low-strength carbon steel. The 4 means about 400 MPa tensile; the .6 means yield is 60% of tensile.
| Marking | 4.6 plus manufacturer ID (required from M5 on marked products) |
|---|---|
| Matching nut | ISO 898-2 class 5 |
Mechanical properties (ISO 898-1)
| Class | Tensile Rm (min) | Yield (min) | Proof stress | Hardness |
|---|---|---|---|---|
| 4.6 | 400 MPa | 240 MPa | 225 MPa | 120 - 220 HV |
These tables carry the same figures as the printed sheet below.
The printed sheet
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Text version of this sheet
ISO 898-1 · property class 4.6 · low strength
FIELD IDENTIFICATION
What it is
Class 4.6 is low-strength carbon steel. The 4 means about 400 MPa tensile; the .6 means yield is 60%
of tensile.
MFG
4.6
Marking
4.6 plus manufacturer ID (required from M5 on marked products)
Matching nut
ISO 898-2 class 5
Head stamped 4.6 + manufacturer ID
Mechanical properties (ISO 898-1)
Class
4.6
Tensile Rm (min)
Yield (min)
400 MPa
Proof stress
240 MPa
Hardness
225 MPa
120 - 220 HV
Key points
Used for light fabrication and non-critical metric hardware.
Governing standards: ISO 898-1:2013; ISO 898-2:2022. Editions shown are the latest confirmed as of September 2026. The drawing and the governing standard always take
precedence over this sheet.
torquing any fastener. Verify the current governing standard, project documents, OEM requirements, size, thread, coating and lot certification. To the fullest extent permitted by law, The Fastener App disclaims liability
arising from reliance on this reference.
Fastener Guide reference FG-4DE632 · thefastenerapp.com/fastener-guide/technical-reference/metric-property-class-4-6 · © The Fastener App. Reference only — verify the current governing standard, drawing and manufacturer data before specifying or installing.
