Spi 14-449-3 Surface Finish Comparator 6 Specimens Nickel

Product Description

The SPI 14-449-3 is a nickel surface finish comparator used to visually and tactilely evaluate machined surface textures. It contains 6 specimens covering a range of 0.2 to 6.3 Ra micrometers, equivalent to 8 to 250 AA microinches. Each specimen represents a distinct finish grade produced by vertical grinding, allowing machinists and quality control technicians to compare a workpiece surface directly against a known standard. The comparator includes an instruction sheet and a protective carrying case. It weighs 0.25 pounds and measures 2.5 inches in length by 5 inches in width overall.

This comparator is used in machine shops, inspection departments, and manufacturing environments where surface finish must be verified against engineering specifications. It is suited for checking ground components in both production and incoming-inspection workflows. Quality technicians, machinists, and metrology personnel use this tool as part of surface texture verification on vertically ground parts. It is not limited to a single industry and is commonly found in aerospace, automotive, and general metalworking applications.

Key Features

• 6 nickel specimens spanning 8, 16, 32, 63, 125, and 250 AA microinches (0.2 to 6.3 Ra micrometers)
• Machining process: vertical grinding — specimens match that specific surface texture pattern
• Dual-scale reference: AA microinch and Ra micrometer values for both Imperial and metric specifications
• Complies with ANSI B46.1-1978, Military Specification 45662, and SAE surface finish standards
• Includes instructions and protective carrying case
• Compact form factor — 2.5 inches by 5 inches overall — for bench or field use

Compatibility

Designed for use as a surface finish reference tool on vertically ground nickel-finish workpieces evaluated to AA and Ra scale standards per ANSI B46.1-1978, Military Specification 45662, and SAE requirements.

Installation Notes

No installation is required. This is a hand-held inspection reference tool. Store specimens in the included case to prevent surface contamination or damage that could affect comparison accuracy. Clean workpiece surfaces before comparison to ensure accurate tactile and visual readings. Handle specimens by the edges to avoid introducing oils or debris onto the reference surfaces.