supply of supply of one set of standard hardness test blocks , supply of one set of standard hardness test blocks, comprising of forty one (41) numbers of test blocks as tabulated in the annexure, suitable for periodical verification of rockwell hardness testing machine, brinell hardness testing machine and vic kers hardness testing machine, as per the requirements of nabl and other equivalent standard requirements. each standard test bl ock shall be supplied along with test certificate issued by nabl accredited laboratory, bearing valid nabl logo with traceability to n ational/international standards as per nabl requirements. detailed technical specification, hardness ranges and quantity as per ann exure. ]