The grades of 6 Energy Equipment & Services stocks are on the rise this week on Portfolio Grader. Each of these stocks is rated an “A” (“strong buy”) or “B” overall (“buy”).

Helmerich & Payne, Inc. (HP) boosts its rating from a C to a B this week. Helmerich & Payne, Inc. provides contract drilling of oil and gas wells in the Gulf of Mexico and South America. For more information, get Portfolio Grader’s complete analysis of HP stock.

This week, Natural Gas Services Group, Inc.’s (NGS) ratings are up from a C last week to a B. Natural Gas Services Group, Inc. manufactures, sells, and rents gas compression and low emissions flare systems. The company also gets A’s in earnings surprise and free cash flow. For more information, get Portfolio Grader’s complete analysis of NGS stock.

This is a strong week for Rowan Cos. Plc Class A (RDC). The company’s rating climbs to B from the previous week’s C. Rowan Cos. Plc Class A provides contract drilling services internationally and domestically. The company also gets A’s in earnings surprise and earnings momentum. For more information, get Portfolio Grader’s complete analysis of RDC stock.

This week, Noble Corporation plc (NE) pushes up from a C to a B rating. Noble Corporation plc is an offshore drilling contractor, engineer, and consultant for the oil and gas industry. The company also gets A’s in earnings momentum and free cash flow. For more information, get Portfolio Grader’s complete analysis of NE stock.

Dawson Geophysical Company (DWSN) shows solid improvement this week. The company’s rating rises from a C to a B. Dawson Geophysical Company provides onshore seismic data acquisition and processing services in the United States. For more information, get Portfolio Grader’s complete analysis of DWSN stock.

Recon Technology Ltd. (RCON) gets a higher grade this week, advancing from a C last week to a B. Recon Technology Ltd. is a holding company that provides services designed to automate the extraction of petroleum in China. The company also gets A’s in sales growth. For more information, get Portfolio Grader’s complete analysis of RCON 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.