This document presents a study on using similarity measure functions to select engineering materials from a database. Thirteen similarity/distance functions are examined to quantify the similarity between materials based on their properties. A performance index measure is used to evaluate how well a selected material matches the target material. The materials are ranked based on their normalized performance index values. An algorithm is presented that takes a target material, calculates similarities to materials in a database using different functions, computes performance indexes, and selects the material with the minimum normalized performance index as the best match. Experimental results applied the approach to select materials from a database of 5670 materials that best match a target material described by 25 properties.