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

Omega Flex’s (NASDAQ:OFLX) rating falls to a D (“sell”) this week, down from C (“hold”) the week prior. Omega Flex manufactures flexible metal hose. The stock price has fallen 9.2% over the past month, worse than the 4.2% increase the Nasdaq has seen over the same period of time. For more information, get Portfolio Grader’s complete analysis of OFLX stock.

Hurco’s (NASDAQ:HURC) rating weakens this week, dropping to a D versus last week’s C. Hurco Companies designs and produces interactive computer controls, software, and computerized machine systems for the worldwide metal cutting and metal forming industry. The stock also gets an F in Earnings Momentum. For a full analysis of HURC stock, visit Portfolio Grader.

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

Douglas Dynamics’ (NYSE:PLOW) rating falls this week to an F (“strong sell”), down from last week’s D (“sell”). Douglas Dynamics designs, makes, and sells snow and ice control equipment for light trucks. The stock gets F’s in Earnings Surprise and Sales Growth. For a full analysis of PLOW 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.