The grades of eight Metals and Mining stocks are better this week, according to the Portfolio Grader database. Every one of these stocks has an “A” (“strong buy”) or “B” overall (“buy”) rating.

MAG Silver’s (AMEX:MVG) grade is moving up to a B (“buy”) this week from last week’s C (“hold”). MAG Silver acquires and explores mineral properties with a focus on high-grade silver and gold. For more information, get Portfolio Grader’s complete analysis of MVG stock.

Keegan Resources (AMEX:KGN) is seeing ratings go up from a C last week to a B this week. Unicode Decode Error. The stock currently has a trailing PE Ratio of 7.90. For more information, get Portfolio Grader’s complete analysis of KGN stock.

This week, Franco-Nevada (NYSE:FNV) is making solid headway. The company’s rating improves to an A (“strong buy”) from last week’s B (“buy”) rating. Franco-Nevada is a resource royalty and investment company. For more information, get Portfolio Grader’s complete analysis of FNV stock.

Harry Winston (NYSE:HWD) earns a B this week, jumping up from last week’s grade of C. Harry Winston Diamond Corp. formerly Aber Diamond Corp. was originally formed on April 19, 1994. Shares of HWD have increased 5.2% over the past month, better than the 3.9% increase the S&P 500 has seen over the same period of time. For more information, get Portfolio Grader’s complete analysis of HWD stock.

Kaiser Aluminum (NASDAQ:KALU) boosts its rating from a B to a A this week. Kaiser Aluminum produces alumina, primary aluminum, and fabricated aluminum products. For more information, get Portfolio Grader’s complete analysis of KALU stock.

The rating of Southern Copper (NYSE:SCCO) moves up this week, rising from a C to a B. Southern Copper is an integrated copper producer. Investors have pushed the stock price up 12.1% over the past month. The current dividend yield is 11%. For more information, get Portfolio Grader’s complete analysis of SCCO stock.

A.M. Castle (NYSE:CAS) improves from a C to a B rating this week. A. M. Castle provides a range of products and value-added processing and supply chain services to customers that are primarily in the producer/durable equipment sector of the global economy. For more information, get Portfolio Grader’s complete analysis of CAS stock.

This week, Almaden Minerals (AMEX:AAU) pushes up from a C to a B rating. Almaden Minerals engages in the acquisition, exploration, and development of mineral properties in Canada, the United States, and Mexico. For more information, get Portfolio Grader’s complete analysis of AAU 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.