This week, four Machinery stocks are improving their overall rating on Portfolio Grader. Each of these rates an “A” (“strong buy”) or “B” overall (“buy”).

Robbins & Myers’ (NYSE:RBN) grade is moving up to a B (“buy”) this week from last week’s C (“hold”). Robbins & Myers supplies engineered equipment and systems for critical applications in global energy, industrial, chemical and pharmaceutical markets. For more information, get Portfolio Grader’s complete analysis of RBN stock.

This week, Lydall (NYSE:LDL) is showing good progress as the company’s rating jumps from a B (“buy”) last week to an A (“strong buy”). Lydall develops and manufactures engineered materials for a variety of applications. For more information, get Portfolio Grader’s complete analysis of LDL stock.

Lincoln Electric Holdings (NASDAQ:LECO) shows solid improvement this week. The company’s rating rises from a C to a B. Lincoln Electric Holdings designs and manufactures welding and cutting products. The stock price has risen 7.1% over the past month, better than the 2.2% increase the Nasdaq has seen over the same period of time. For more information, get Portfolio Grader’s complete analysis of LECO stock.

Manitex International (NASDAQ:MNTX) is seeing ratings go up from a B last week to an A this week. Manitex International designs, develops and builds integrated production-line assembly and testing equipment for the automotive and heavy equipment industries. Wall Street has pushed the stock higher by 31.2% over the past month. For more information, get Portfolio Grader’s complete analysis of MNTX 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.