JIS Z 2251:2009 PDF

Scope: This Standard specifies the Knoop hardness test method for metallic materials, for test forces from 0.098 07 N to 19.614 N. The method is recommended only for indenta- tions with diagonals ≥ 0.020 mm. NOTE: The International Standards corresponding to this Standard is as fol- lows. ISO 4545-1 : 2005 Metallic materials- Knoop hardness test- Part 1 : Test method ISO 4545-4 : 2005 Metallic materials -- Knoop hardness test- Part 4 : Table of hardness values (Overall evaluation : MOD) In addition, symbols which denote the degree of correspondence in the contents between the relevant International Standards and JIS are IDT (identical), MOD (modified), and NEQ (not equivalent) according to ISO/IEC Guide 21.

JIS Z 2251:2009 Referenced Document

ISO 4545-3 Metallic materials - Knoop hardness test- Part 3:Calibration of reference blocks*， 2017-12-14 Update
JIS B 7734 Knoop hardness test -- Verification and calibration of testing machines*， 2020-12-21 Update