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”).

Hurco Companies, Inc.’s (HURC) rating falls this week to an F (“strong sell”), down from last week’s D (“sell”). Hurco Companies designs and produces interactive computer controls, software, and computerized machine systems for the worldwide metal cutting and metal forming industry. For more information, get Portfolio Grader’s complete analysis of HURC stock.

This week, Kaydon Corporation’s (KDN) rating worsens to an F from the company’s D rating a week ago. Kaydon designs, manufactures, and sells custom-engineered products for a variety of industries, including aerospace, defense, and industrial. The stock receives F’s in Earnings Growth, Earnings Momentum, Cash Flow and Margin Growth. 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.

Valmont Industries, Inc. (VMI) is having a tough week. The company’s rating falls from a D to an F. Valmont Industries manufactures fabricated metal products and mechanized irrigation systems. As of Sept. 26, 2014, 22.5% of outstanding Valmont Industries, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of VMI stock.

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. The stock also rates an F in Earnings Surprise. Shares of the stock have been changing hands at an unusually rapid pace, three times the rate of the week prior. To get an in-depth look at TRS, get Portfolio Grader’s complete analysis of TRS stock.

This week, Stanley Black & Decker, Inc. (SWK) drops from a C to a D rating. 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.

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.