This week, four metals and mining stocks are improving their overall ratings on Portfolio Grader. Each of these stocks is rated an “A” (“strong buy”) or “B” overall (“buy”).

U.S. Silica Holdings, Inc. (SLCA) is bettering its rating of C (“hold”) from last week to a B (“buy”) this week. U.S. Silica Holdings engages in the mining, processing, and sale of commercial silica in the United States. In Portfolio Grader’s specific subcategories of Equity and Sales Growth, SLCA also gets A’s. Shares of the stock have been changing hands at an unusually rapid pace, twice the rate of the week prior. For more information, get Portfolio Grader’s complete analysis of SLCA stock.

Richmont Mines (RIC) is making headway this week, with the company’s rating improving to an A (“strong buy”) from a B (“buy”) last week. Richmont Mines owns and operates the Francoeur, Beaufor and East Amphi mines located in Quebec, the Nugget Pond and Hammerdown mines in Newfoundland, and the Island Gold Mine in Ontario. For more information, get Portfolio Grader’s complete analysis of RIC stock.

Ternium S.A. Sponsored ADR (TX) is seeing ratings go up from a C last week to a B this week. Ternium is a steel company that makes flat and long steel products for customers engaged in the construction, home appliances, capital goods, container, food, energy and automotive industries. Shares of the stock have been changing hands at an unusually rapid pace, three times the rate of the week prior. For more information, get Portfolio Grader’s complete analysis of TX stock.

This is a strong week for Synalloy Corporation (SYNL). The company’s rating climbs to B from the previous week’s C. Synalloy engages in metals and specialty chemicals businesses in the United States and internationally. For more information, get Portfolio Grader’s complete analysis of SYNL stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.