This week, four machinery stocks are improving their overall ratings on Portfolio Grader. Each of these stocks is rated an “A” (“strong buy”) or “B” overall (“buy”).

Pentair Ltd.’s (PNR) grade is moving up to a B (“buy”) this week from last week’s C (“hold”). Pentair produces electrical and electronic enclosures, professional tools, and water products. In Portfolio Grader’s specific subcategories of Earnings Growth, Margin Growth and Sales Growth, PNR also gets A’s. For more information, get Portfolio Grader’s complete analysis of PNR stock.

Meritor, Inc. (MTOR) earns a B this week, jumping up from last week’s grade of C. Meritor is a global supplier of drivetrain, mobility, braking and aftermarket solutions for commercial vehicle and industrial markets. For more information, get Portfolio Grader’s complete analysis of MTOR stock.

The Manitowoc Company, Inc. (MTW) improves from a C to a B rating this week. Manitowoc is a diversified industrial manufacturer of cranes and related products and food service equipment. The stock price has risen 14% over the past month, better than the 1.7% decrease the S&P 500 has seen over the same period of time. For more information, get Portfolio Grader’s complete analysis of MTW stock.

IDEX Corporation (IEX) boosts its rating from a C to a B this week. Idex designs, manufactures, and markets a variety of pump products, dispensing equipment, and other engineered products. For more information, get Portfolio Grader’s complete analysis of IEX 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.