Square Sign Posts Posts are manufactured conforming to FHWA and ATSSA standard. Steel material conforms to ASTM A1011, Grade 50. Yield strength after cold-forming is 60,000 psi minimum. Posts are manufactured from hot-dipped galvanized steel conforming to ASTM A653, G90 or G140. The posts are also coated with a chromate conversion coating and a clear organic polymer topcoat. Punching with 7/16" holes on 1" centers on all four sides down the entire length of the post. Five kinds of cross section including 1.50â?�X1.50", 1.75", 2.00", 2.25", and 2.50"X2.50". Available in 12 and 14 gauge thickness with all kinds of length according to your demand. Powder coated sign posts with all kinds of colors are also available.