Gilmore Diamond Tools - Diamond Indenters

IMPORTANT ANNOUNCEMENT

Gilmore Diamond Tools, Inc.

Gilmore Diamond calibration Laboratory was awarded NVLAP Lab status by NIST on
January 18, 2006. This makes Gilmore Diamond Tools the only Rockwell diamond indenter manufacturer in the country with the ability to make, calibrate, and certify Rockwell diamond indenter compliance with ASTM E18 and / or ISO 6508 requirements in an ISO/IEC 17025 compliant Laboratory. This provides our customers traceability to the National Standard.

This is important news for the Rockwell hardness testing community. ASTM E-18 is currently in the approval cycle for a new draft revision, which aligns the US specifications with the globally adhered to ISO specification. The new draft, among other things, creates three grades (two new grades) of Rockwell diamond indenters. The Reference Grade is the highest quality, Grade A (new calibration grade), and finally Grade B (present working grade) indenters. All three grades share the same geometrical specifications, however the tolerance in deviation from the nominal is much tighter for the Reference Grade. The requirements are shown in the table below.

Geometrical Feature	Reference Grade Tolerance	Grade A, B Tolerance
Included Cone Angle	120^o +/- 0.10^o	120^o +/- 0.35^o
Tip Mean Radius	.200mm +/- .005mm (.007mm max deviation in any 1 section of 8 measured.)	.200mm +/- .010mm (.015mm max deviation in any 1 section of 4 measured)
Cone Straightness	Max deviation of .001mm over 0.4mm	Max deviation of .002mm over 0.4mm
Seating Surface to Tip Axial offset	0.3^o Max	0.5^o Max

Traditional diamond tool manufacturing techniques are still acceptable for Class B indenter production, however the more stringent tolerances of the higher Grade indenters can not be produced consistently using traditional methods.

Several years ago NIST (National Institute of Standards and Technology) initiated a National Rockwell Hardness Standards Program with the ultimate goal of providing Standard Reference Materials (SRM) to industry with traceability to the National Standard.

The capability to consistently manufacture Reference Grade diamond indenters was precisely the goal of Dept. of Commerce Phase II research performed here at Gilmore. A successful conclusion has been attained and Gilmore Diamond Tools is now capable of providing NIST, domestic and foreign industry, as well as Standardizing Agencies worldwide with a reliable source for Reference grade Rockwell diamond indenters, as well as Grade A and B penetrators.