This week, the overall grades of nine machinery stocks are lower, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Hyster-Yale Materials Handling, Inc. Class A (HY) earns an F (“strong sell”) this week, moving down from last week’s grade of D (“sell”). In Portfolio Grader’s specific subcategories of Earnings Revisions and Earnings Surprise, HY also gets F’s. Shares of the stock have been exchanging at an usually rapid pace, twice the rate of the week prior. To get an in-depth look at HY, get Portfolio Grader’s complete analysis of HY stock.

Trinity Industries, Inc.’s (TRN) rating falls to a D (“sell”) this week, down from C (“hold”) the week prior. Trinity Industries is engaged in the manufacture and sale of railcars and railcar parts, inland barges, structural wind towers, concrete and aggregates, asphalt, highway products and structural steel components. The stock also rates an F in Earnings Momentum. As of May 15, 2015, 13.1% of outstanding Trinity Industries, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of TRN stock.

This is a rough week for American Railcar Industries, Inc. (ARII). The company’s rating falls to D from the previous week’s C. American Railcar Industries designs, manufactures, and sells hopper and tank railcars in North America. The stock gets F’s in Cash Flow and Sales Growth. To get an in-depth look at ARII, get Portfolio Grader’s complete analysis of ARII stock.

The rating of Manitowoc Company, Inc. (MTW) slips from a D to an F. Manitowoc is a diversified industrial manufacturer of cranes and related products and food service equipment. The stock gets F’s in Earnings Revisions and Earnings Surprise. As of May 15, 2015, 12.2% of outstanding Manitowoc Company, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of MTW stock.

Watts Water Technologies, Inc. Class A (WTS) earns a D this week, moving down from last week’s grade of C. Watts Water Technologies designs, manufactures and sells a line of water safety and flow control products for the water quality, water conservation, water safety and water flow control markets. The stock gets F’s in Earnings Revisions and Earnings Surprise. Shares of the stock are changing hands at twice the rate they were a week ago. The trailing PE Ratio for the stock is 40.10. To get an in-depth look at WTS, get Portfolio Grader’s complete analysis of WTS stock.

This week, Kaydon Corporation (KDN) drops from a D to an F rating. Kaydon designs, manufactures, and sells custom-engineered products for a variety of industries, including aerospace, defense, and industrial. In Earnings Growth, Earnings Momentum, Cash Flow and Margin Growth the stock gets F’s. The stock currently has a trailing PE Ratio of 37.20. For more information, get Portfolio Grader’s complete analysis of KDN stock.

Sun Hydraulics Corporation (SNHY) earns a D this week, falling from last week’s grade of C. Sun Hydraulics designs and manufactures high-performance screw-in hydraulic cartridge valves and manifolds, which control force, speed and motion as integral components in fluid power systems. To get an in-depth look at SNHY, get Portfolio Grader’s complete analysis of SNHY stock.

Dover Corporation (DOV) gets weaker ratings this week as last week’s C drops to a D. Dover owns and operates a global portfolio of manufacturing companies that provide components and equipment, specialty systems and support services in the industrial products, engineered systems, fluid management and electronic technologies markets. For more information, get Portfolio Grader’s complete analysis of DOV stock.

Slipping from a D to an F rating, CIRCOR International, Inc. (CIR) takes a hit this week. CIRCOR designs, manufactures, and markets highly-engineered products, such as valves, that control the flow of fluids safely and efficiently in the energy, aerospace, and industrial markets. The stock gets F’s in Earnings Revisions and Sales Growth. To get an in-depth look at CIR, get Portfolio Grader’s complete analysis of CIR 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.