The ratings of 4 Machinery stocks are down this week, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Cummins Inc. (CMI) earns a F this week, moving down from last week’s grade of D. Cummins Inc. designs, manufactures, distributes and services diesel and natural gas engines, electric power generation systems, and engine-related component products. The company also gets F’s in earnings surprise. For more information, get Portfolio Grader’s complete analysis of CMI stock.

Watts Water Technologies, Inc. Class A (WTS) gets weaker ratings this week as last week’s C drops to a D. Watts Water Technologies, Inc. Class A designs, manufactures and sells a line of water safety and flow control products for the water quality, water conservation, water safety and water flow control markets. The company also gets F’s in earnings momentum. For more information, get Portfolio Grader’s complete analysis of WTS stock.

CIRCOR International, Inc. (CIR) slips from a D to a F this week. CIRCOR International, Inc. designs, manufactures, and markets highly-engineered products, such as valves, that control the flow of fluids safely and efficiently in the energy, aerospace, and industrial markets. The company also gets F’s in sales growth. For more information, get Portfolio Grader’s complete analysis of CIR stock.

ExOne Co.’s (XONE) rating weakens this week, dropping to a F versus last week’s D. The company also gets F’s in sales growth, earnings revisions, earnings surprise, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of XONE 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.