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

This week, TriMas Corporation (TRS) falls to a D (“sell”), worse than last week’s grade of C (“hold”). 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.

Stanley Black & Decker, Inc. (SWK) gets weaker ratings this week as last week’s C drops 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) ratings are on the decline this week as the company earns an F (“strong sell”). Last week, it received a D (“sell”). Valmont Industries manufactures fabricated metal products and mechanized irrigation systems. As of May 23, 2014, 11% of outstanding Valmont Industries, Inc. shares were held short. Shares of the stock have been trading at an exceptionally rapid pace, up twofold from the week prior. For a full analysis of VMI stock, visit Portfolio Grader.

Kaydon Corporation (KDN) earns an F this week, moving down from last week’s grade of 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 trailing PE Ratio for the stock is 37.20. For more information, 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. To get an in-depth look at HURC, get Portfolio Grader’s complete analysis of HURC 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.