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

AAON, Inc.’s (AAON) grade is moving up to a B (“buy”) this week from last week’s C (“hold”). AAON manufactures and sells air-conditioning and heating equipment. In Portfolio Grader’s specific subcategory of Earnings Momentum, AAON also gets an A. For more information, get Portfolio Grader’s complete analysis of AAON stock.

NCI Building Systems, Inc. (NCS) improves from a C to a B rating this week. NCI Building Systems designs, manufactures, and markets metal engineered building systems and products for the building industry. Shares of NCS have increased 7.8% over the past month, better than the 1.7% decrease the S&P 500 has seen over the same period of time. Shares of the stock have been changing hands at an unusually rapid pace, up 642.6% from the week prior. For more information, get Portfolio Grader’s complete analysis of NCS stock.

Masonite International Corp. (DOOR) is making headway this week, with the company’s rating improving to an A (“strong buy”) from a B (“buy”) last week. Masonite International manufactures and markets interior and exterior door products worldwide. Wall Street has pushed the stock higher by 5.2% over the past month. For more information, get Portfolio Grader’s complete analysis of DOOR stock.

PGT, Inc. (PGTI) shows solid improvement this week. The company’s rating rises from a B to an A. PGT manufactures and supplies residential impact-resistant windows and doors. The stock has inched up 9.4% over the past week. 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.