Spi 12-681-3 Steel Gage Block 0.131 in Grade 0 Nist

Product Description

The SPI 12-681-3 is a rectangular steel gage block ground and lapped to a nominal size of 0.131 inches at Grade 0 accuracy. Gage blocks are precision reference standards used to calibrate measuring instruments, set comparators, and verify dimensional tolerances on machined parts. This block includes NIST certification, providing a traceable accuracy record required in quality-controlled shop and metrology lab environments. Grade 0 represents a high level of dimensional accuracy, making this block suitable for calibration and inspection work where tight tolerances must be verified. It is a single-block unit intended for individual use or incorporation into a larger gage block set.

This gage block is used in machine shops, tool rooms, metrology labs, and quality inspection departments. Typical applications include setting dial indicators and comparators, verifying the calibration of micrometers and calipers, and establishing precise reference dimensions during precision machining setups. The 0.131-inch size is a common increment found in fractional and decimal inch gage block sets. NIST certification makes this block appropriate for facilities operating under ISO, AS9100, or other quality management standards that require traceable measurement references.

Key Features

• Grade 0 accuracy for calibration and high-precision inspection work
• Nominal size of 0.131 inches for use as a dimensional reference standard
• Steel construction for durability and stable dimensional properties
• Includes NIST certification providing traceable accuracy documentation
• Rectangular form compatible with standard gage block accessories and holders

Compatibility

Designed as an individual Grade 0 rectangular steel gage block for use as a standalone calibration reference or as part of a decimal inch gage block set in machine shop and metrology applications.

Installation Notes

Gage blocks should be handled by a qualified metrologist or machinist familiar with wringing technique and proper block care. Store blocks in a protective case away from moisture, temperature extremes, and contaminants that can cause corrosion or dimensional drift. Clean blocks with an appropriate instrument-grade solvent before and after use. Never slide blocks against hard abrasive surfaces, as surface damage will compromise accuracy and invalidate the NIST certification record.