This week, the ratings of 7 Energy Equipment & Services stocks on Portfolio Grader are down. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

This week, Dril-Quip, Inc. (DRQ) drops from a C to a D rating. Dril-Quip, Inc. designs, manufactures, sells, and services offshore drilling and production equipment to be used in deepwater, harsh environment, and severe service applications. The company also gets F’s in sales growth. For more information, get Portfolio Grader’s complete analysis of DRQ stock.

U.S. Silica Holdings, Inc. (SLCA) slips from a C to a D this week. U.S. Silica Holdings, Inc. engages in the mining, processing, and sale of commercial silica in the United States. The company also gets F’s in sales growth, earnings growth, earnings revisions, and earnings momentum. For more information, get Portfolio Grader’s complete analysis of SLCA stock.

Slipping from a C to a D rating, USA Compression Partners LP (USAC) takes a hit this week. The company also gets F’s in earnings momentum and free cash flow. For more information, get Portfolio Grader’s complete analysis of USAC stock.

This week, CSI Compressco LP’s (CCLP) rating worsens to a D from the company’s C rating a week ago. The company also gets F’s in operating margin growth, earnings surprise, and free cash flow. For more information, get Portfolio Grader’s complete analysis of CCLP stock.

Unit Corporation (UNT) gets weaker ratings this week as last week’s D drops to a F. Unit Corporation is a contract drilling company that engages in land drilling of natural gas and oil wells. The company also gets F’s in sales growth, operating margin growth, earnings growth, earnings momentum, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of UNT stock.

Aspen Aerogels Inc (ASPN) earns a D this week, moving down from last week’s grade of C. The company also gets F’s in earnings momentum, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of ASPN stock.

Fairmount Santrol Holdings, Inc.’s (FMSA) rating weakens this week, dropping to a F versus last week’s D. The company also gets F’s in sales growth, operating margin growth, earnings growth, earnings revisions, earnings momentum, and free cash flow. For more information, get Portfolio Grader’s complete analysis of FMSA 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.