This week, the ratings of 10 metals and mining stocks on Portfolio Grader are down. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

This week, Primero Mining Corp. (PPP) falls to a D (“sell”), worse than last week’s grade of C (“hold”). Primero Mining is focused on building precious metals assets in the Americas through acquiring, exploring, developing and operating mineral resource properties. In Portfolio Grader’s specific subcategories of Earnings Growth, Earnings Momentum, Earnings Revisions, Cash Flow and Margin Growth, PPP also gets F’s. For more information, get Portfolio Grader’s complete analysis of PPP stock.

North American Palladium’s (PAL) rating falls this week to an F (“strong sell”), down from last week’s D (“sell”). North American Palladium is a mineral exploration and production company. The stock gets F’s in Earnings Revisions, Equity and Cash Flow. To get an in-depth look at PAL, get Portfolio Grader’s complete analysis of PAL stock.

Slipping from a C to a D rating, Alamos Gold Inc. (AGI) takes a hit this week. Alamos Gold acquires, explores, develops and produces gold. The stock gets F’s in Earnings Growth, Margin Growth and Sales Growth. For more information, get Portfolio Grader’s complete analysis of AGI stock.

Constellium NV Class A (CSTM) earns an F this week, moving down from last week’s grade of D. The stock receives F’s in Earnings Growth, Earnings Revisions, Earnings Surprise and Sales Growth. To get an in-depth look at CSTM, get Portfolio Grader’s complete analysis of CSTM stock.

This week, Allied Nevada Gold’s (ANV) rating worsens to an F from the company’s D rating a week ago. Allied Nevada Gold engages in the evaluation, acquisition, exploration, and advancement of gold exploration and development projects. The stock gets F’s in Earnings Growth, Earnings Revisions and Equity. Cash Flow and Margin Growth also get F’s. As of Jan. 30, 2015, 26.3% of outstanding Allied Nevada Gold shares were held short. For more information, get Portfolio Grader’s complete analysis of ANV stock.

Keegan Resources (KGN) experiences a ratings drop this week, going from last week’s C to a D. Keegan Resources, a junior gold company, engages in the exploration and development of gold properties in Ghana, west Africa. The stock gets F’s in Equity and Cash Flow. To get an in-depth look at KGN, get Portfolio Grader’s complete analysis of KGN stock.

The rating of POSCO Sponsored ADR (PKX) declines this week from a C to a D. POSCO produces hot rolled steel, cold rolled steel, stainless steel, and other forms of steel. The stock gets F’s in Earnings Growth and Sales Growth. For more information, get Portfolio Grader’s complete analysis of PKX stock.

This week, SunCoke Energy Partners LP (SXCP) drops from a C to a D rating. The stock also gets an F in Earnings Revisions. To get an in-depth look at SXCP, get Portfolio Grader’s complete analysis of SXCP stock.

Cliffs Natural Resources (CLF) is having a tough week. The company’s rating falls from a D to an F. Cliffs Natural Resources is an international mining and natural resources company. The stock gets F’s in Earnings Growth, Earnings Momentum, Cash Flow and Sales Growth. As of Jan. 30, 2015, 43.6% of outstanding Cliffs Natural Resources shares were held short. For more information, get Portfolio Grader’s complete analysis of CLF stock.

The rating of SunCoke Energy, Inc. (SXC) slips from a D to an F. SunCoke Energy, in addition to mining and producing coal in the Americas, offers metallurgical and thermal coal used in steelmaking facilities. The stock gets F’s in Earnings Momentum, Earnings Revisions and Margin Growth. To get an in-depth look at SXC, get Portfolio Grader’s complete analysis of SXC 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.