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

AAON (NASDAQ:AAON) ups its rating to a B (“buy”) this week after earning a C (“hold”) in the week before. AAON manufactures and sells air-conditioning and heating equipment. In Portfolio Grader’s specific subcategory of Earnings Momentum, AAON also gets an A. The stock price has risen 6.8% over the past month, better than the 1% decrease the Nasdaq has seen over the same period of time. For more information, get Portfolio Grader’s complete analysis of AAON stock.

This is a strong week for NCI Building Systems (NYSE:NCS). The company’s rating climbs to B from the previous week’s C. NCI Building Systems designs, manufactures, and markets metal engineered building systems and products for the building industry. For more information, get Portfolio Grader’s complete analysis of NCS stock.

This week, PGT Inc. (NASDAQ:PGTI) is showing good progress as the company’s rating jumps from a B (“buy”) last week to an A (“strong buy”). PGT manufactures and supplies residential impact-resistant windows and doors. For more information, get Portfolio Grader’s complete analysis of PGTI 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.