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) ratings are on the decline this week as the company earns an F (“strong sell”). Last week, it received a D (“sell”). In Portfolio Grader’s specific subcategories of Earnings Revisions and Earnings Surprise, HY also gets F’s. For more information, get Portfolio Grader’s complete analysis of HY stock.

This week, Trinity Industries, Inc. (TRN) falls to a D (“sell”), worse than last week’s grade of C (“hold”). 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 gets an F in Earnings Momentum. As of March 27, 2015, 13.3% of outstanding Trinity Industries, Inc. shares were held short. To get an in-depth look at TRN, get Portfolio Grader’s complete analysis of TRN stock.

This week, American Railcar Industries, Inc.’s (ARII) rating worsens to a D from the company’s C rating a week ago. 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. For more information, get Portfolio Grader’s complete analysis of ARII stock.

Manitowoc Company, Inc. (MTW) is having a tough week. The company’s rating falls 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 March 27, 2015, 11.2% of outstanding Manitowoc Company, Inc. shares were held short. To get an in-depth look at MTW, get Portfolio Grader’s complete analysis of MTW stock.

Slipping from a C to a D rating, Watts Water Technologies, Inc. Class A (WTS) takes a hit this week. 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. The stock has a trailing PE Ratio of 38.50. For more information, get Portfolio Grader’s complete analysis of WTS stock.

Kaydon Corporation’s (KDN) rating weakens this week, dropping to an F versus last week’s D. Kaydon designs, manufactures, and sells custom-engineered products for a variety of industries, including aerospace, defense, and industrial. The stock gets F’s in Earnings Growth, Earnings Momentum, Cash Flow and Margin Growth. The trailing PE Ratio for the stock is 37.20. To get an in-depth look at KDN, get Portfolio Grader’s complete analysis of KDN stock.

The rating of Sun Hydraulics Corporation (SNHY) declines this week from a C to a D. 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. For more information, 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. To get an in-depth look at DOV, get Portfolio Grader’s complete analysis of DOV stock.

CIRCOR International, Inc. (CIR) earns an F this week, moving down from last week’s grade of D. 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. For more information, 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.