DIN EN 10328 is a steel testing standard used to determine the conventional depth of hardening after surface heating processes (surface hardening). It is commonly applied when verifying flame- or induction-hardened layers by measuring a hardness profile from the surface into the core.
If you need help matching your drawing or customer requirement to the correct edition (or to the replacement standard), you can contact our team to discuss what you are trying to measure and report.
DIN EN 10328: Iron and steel — Determination of the conventional depth of hardening after surface heating
DIN EN 10328 is used to quantify how far a surface-hardened layer extends into a steel part after a surface heating hardening process. The standard’s outcome is a depth value based on a measured hardness gradient in cross-section.
Quick definition
What it is: A test method for determining conventional hardening depth after surface heating by evaluating a hardness profile measured from the surface inward on a prepared cross-section.
What you get: A defined hardening depth value derived from hardness-versus-depth results (often presented as a curve) and the associated test conditions used to produce the profile.
What this standard covers
This standard covers a practical approach for determining hardening depth in steel after surface heating hardening by measuring hardness at increasing distances from the surface on a cross-section.
It is typically used where the hardened layer is not just a surface reading, but a depth-dependent property that must be demonstrated against a specification, drawing note, or process validation requirement.
Why this standard matters in testing
Surface hardening is used to increase wear resistance and fatigue performance while maintaining a tougher core. DIN EN 10328 provides a consistent way to report hardening depth so results can be compared across suppliers, heat treaters, and labs.
From a lab workflow standpoint, the standard helps avoid ambiguous “case depth” reporting by tying the depth result to a measured hardness profile in a cross-section.
Common materials, product types, or applications covered
DIN EN 10328 is used in steel components that receive localized surface hardening by surface heating methods.
Common examples: Shafts, wear surfaces, bearing seats, gear-related surfaces, and other machine elements where a hardened surface layer is required with a tougher interior.
Common test or verification workflow
A typical DIN EN 10328 verification sequence centers on producing a reliable hardness-versus-depth traverse on a cross-section.
- Section the part to expose a representative cross-section through the hardened region.
- Prepare the cross-section surface (mounting as needed, then grinding/polishing) to support repeatable hardness indentations.
- Make a series of hardness measurements starting near the surface and moving inward at defined spacing.
- Plot hardness versus distance from the surface and determine the conventional depth of hardening per the standard’s definition and criteria.
- Report the depth result along with the measurement conditions used for the hardness profile.
Equipment commonly used for this standard
DIN EN 10328 typically points to hardness profiling equipment and metallographic sample preparation tools rather than a mechanical test frame.
Common equipment: Hardness tester suitable for making a controlled traverse (often microhardness or low-load hardness depending on layer thickness), sample sectioning saw, mounting tools (if used), grinding and polishing equipment, and a measuring system to accurately locate indentation positions from the surface.
For higher throughput and repeatability, many labs use hardness systems with automated stage movement and data capture for hardness-depth curves. If you are selecting equipment for profiling and reporting, you can request a detailed quote based on your expected layer thickness range, sample geometry, and reporting needs.
How to read this designation or revision
Common citation: DIN EN 10328:2005-04.
Status: This DIN EN document has been withdrawn and replaced by DIN EN ISO 18203:2022-07. When a purchase order, drawing, or heat treat specification cites “DIN EN 10328,” confirm whether the requirement intends the withdrawn 2005 edition or the newer replacement standard, since acceptance criteria and reporting expectations can be revision-sensitive.
Related standards, methods, or frameworks
For current projects, DIN EN ISO 18203 is the key successor document used for determining the thickness of surface-hardened layers in steel.
If a legacy specification references earlier national approaches, DIN EN 10328 also replaced DIN 50190-2.
Talk through your hardening-depth requirement
If you are setting up a hardness traverse for surface-hardened steel and want help aligning sample prep, measurement spacing, and reporting to the cited standard and edition, talk with our team about your part, hardening process, and required documentation.