The grades of 4 Building Products stocks are better this week, according to the Portfolio Grader database. Every one of these stocks has an “A” (“strong buy”) or “B” overall (“buy”) rating.

This week, Lennox International Inc. (LII) pushes up from a B to a A rating. Lennox International Inc. designs, manufactures, and markets heating, ventilation, air conditioning, and refrigeration equipment. The company also gets A’s in return on equity. For more information, get Portfolio Grader’s complete analysis of LII stock.

Apogee Enterprises, Inc. (APOG) boosts its rating from a C to a B this week. Apogee Enterprises, Inc. provides technologies that involve the design and development of value-added glass products, and related services and systems. The company also gets A’s in earnings growth. For more information, get Portfolio Grader’s complete analysis of APOG stock.

This is a strong week for AAON, Inc. (AAON). The company’s rating climbs to B from the previous week’s C. AAON, Inc. manufactures and sells air-conditioning and heating equipment. The company also gets A’s in return on equity. For more information, get Portfolio Grader’s complete analysis of AAON stock.

Griffon Corporation (GFF) earns a B this week, jumping up from last week’s grade of C. Griffon Corporation manufactures building products, specialty plastic films, and electronic information and communication systems. The company also gets A’s in operating margin growth. For more information, get Portfolio Grader’s complete analysis of GFF 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.