ISO 10250-1994 PDF

Full title and description

ISO 10250:1994 — Metallic materials — Hardness testing — Tables of Knoop hardness values for use in tests made on flat surfaces. This document provides tabulated values and calculation support for converting indentation measurements into Knoop hardness numbers for use with Knoop hardness testing on flat specimens.

Abstract

ISO 10250:1994 supplies tables for the calculation of Knoop hardness values to be used with Knoop hardness tests carried out on flat surfaces (in conjunction with the relevant ISO Knoop test method). The tables allow users to convert measured indentation diagonals to Knoop hardness numbers without recalculating from the formula for each measurement.

General information

• Status: Withdrawn.
• Publication date: September 1994 (1994-09).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 77.040.10 (Mechanical testing of metals; hardness testing).
• Edition / version: Edition 1 (1994).
• Number of pages: 21 pages.

These bibliographic details are recorded in the ISO catalogue entry for ISO 10250:1994.

Scope

This standard provides tables to calculate Knoop hardness values from indentation measurements for tests made on flat surfaces. It is intended to be used alongside the ISO Knoop hardness test method (ISO 4545 series) and is limited to the conversion/tables aspect rather than prescribing the test procedure itself. The standard was prepared by ISO/TC 164/SC 3 (mechanical testing of metals).

Key topics and requirements

• Tabulated Knoop hardness values covering a defined range of indentation diagonals for conversion to HK (Knoop hardness) values.
• Intended use with Knoop hardness testing on flat specimen surfaces (complementary to the ISO 4545 Knoop test method).
• Provides a practical alternative to repeated formula-based calculations for routine hardness measurement reporting and quality control.
• Prepared under ISO/TC 164/SC 3 — harmonized with later parts of the ISO 4545 series.

Typical use and users

Used by metallurgical and materials testing laboratories, quality assurance and inspection teams in industry, research laboratories, and standards committees that perform or validate Knoop hardness measurements on metallic specimens (flat surfaces). It served as a reference table for testers who needed quick, reproducible conversions from indentation measurements to Knoop hardness values.

Related standards

ISO 10250:1994 is linked to the ISO 4545 series (Knoop hardness test methods). ISO 10250:1994 was withdrawn and its table function was taken up and revised within the ISO 4545 series (notably ISO 4545-4:2005 and the later consolidated ISO 4545-4:2017 table of hardness values). Users should refer to the current part of ISO 4545 for the authoritative, maintained tables and test method details.

Keywords

Knoop; Knoop hardness; hardness tables; metallic materials; hardness testing; indentation; ISO 10250; ISO 4545; HK; hardness conversion.

FAQ

Q: What is this standard?

A: ISO 10250:1994 is an ISO standard that provided tables of Knoop hardness values for use with Knoop hardness tests on flat surfaces. It gave pre-calculated values to convert measured indentation diagonals into Knoop hardness numbers (HK).

Q: What does it cover?

A: It covers tabulated Knoop hardness values (tables and related calculation guidance) for use with Knoop hardness measurements on flat specimens. It does not itself define the full test procedure — that is covered by the ISO 4545 series.

Q: Who typically uses it?

A: Metallurgists, materials testing and QA laboratories, inspection engineers, and standards/technical committees involved in hardness testing and materials characterization historically used this standard as a reference for converting indentation measurements to HK values.

Q: Is it current or superseded?

A: ISO 10250:1994 has been withdrawn. Its table function has been superseded and incorporated into later parts of the ISO 4545 series (notably ISO 4545-4:2005 and the current ISO 4545-4:2017). For current practice and maintained tables, consult the applicable, published part of ISO 4545.

Q: Is it part of a series?

A: Indirectly — ISO 10250 was a companion/tables document used with the ISO 4545 Knoop test method series. Later developments consolidated table content into ISO 4545 parts (especially the Part 4 table of hardness values).

Q: What are the key keywords?

A: Knoop, HK, hardness table, hardness conversion, indentation diagonal, metallic materials, hardness testing, ISO 10250, ISO 4545.