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

TriMas Corporation (TRS) is on the decline this week, earning a D (“sell”) after receiving a C (“hold”) last week. TriMas manufactures trailer products, recreational accessories, packaging systems, energy products and industrial specialty products for the commercial, manufacturing, and consumer markets. TRS also rates an F in Portfolio Grader’s specific subcategory of Earnings Surprise. To get an in-depth look at TRS, get Portfolio Grader’s complete analysis of TRS stock.

The rating of Stanley Black & Decker, Inc. (SWK) declines this week from a C to a D. Stanley Black & Decker is a worldwide supplier of tools and engineered solutions for professional, industrial, construction and do-it-yourself use. For more information, get Portfolio Grader’s complete analysis of SWK stock.

Valmont Industries, Inc. (VMI) earns an F (“strong sell”) this week, moving down from last week’s grade of D (“sell”). Valmont Industries manufactures fabricated metal products and mechanized irrigation systems. As of May 9, 2014, 11.6% of outstanding Valmont Industries, Inc. shares were held short. For a full analysis of VMI stock, visit Portfolio Grader.

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. 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. To get an in-depth look at KDN, get Portfolio Grader’s complete analysis of KDN stock.

This week, Hurco Companies, Inc. (HURC) drops from a D to an F rating. Hurco Companies designs and produces interactive computer controls, software, and computerized machine systems for the worldwide metal cutting and metal forming industry. The stock price has dropped 6.4% over the past month, worse than the 1.3% decrease the Nasdaq has seen over the same period of time. Shares of the stock have been changing hands at an unusually rapid pace, three times the rate of the week prior. For a full analysis of HURC stock, visit Portfolio Grader.

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.