Granite Surface Plate With Precision Ground Top For Ultra Flatness And Stability Grade B Metrology Plate 12 Inch By 9 Inch By 3 Inch Flatness Tolerance 0.0001 Inch Includes Certificate Of Inspection Federal Spec GGG-P-463C Compliant HHIP

Ultra-Flat Granite Surface Plate 12 x 9 x 3 in
✔️ Flatness ±0.0001 in, Grade B, certificate included

This precision granite surface plate provides a rock-solid reference surface for measuring flatness, squareness, and for laying out parts, calibrating instruments, and checking tooling setups in metrology labs and workshop floors. This is a single plate (12 x 9 x 3 in / 304.8 x 228.6 x 76.2 mm), Grade B, with a Certificate of Inspection. It meets Federal Spec GGG-P-463C and is non-magnetic and non-conductive; note it is not NIST traceable.

✅ Size: 12 x 9 x 3 in (304.8 x 228.6 x 76.2 mm)
✅ Flatness: ±0.0001 in (0.00254 mm)
✅ Material: granite; non-magnetic and non-conductive
✅ Compliance: meets GGG-P-463C; Certificate of Inspection included

💡 What is a granite surface plate used for in precision metrology and layout?

This is a handy, stable reference surface for checking flatness and squareness, plus laying out parts and setting up tools. - handy reference for height measurement with a height gage - supports accurate tool setup, inspection, and marking - non-magnetic and non-conductive for clean operations