The "A36" designation is an alphanumeric identifier assigned by ASTM.
"A" indicates it is a ferrous metal specification.
"36" historically signified a minimum yield strength of 36 kilo-pounds per square inch (ksi). This is its defining mechanical property: 36 ksi = 36,000 psi ≈ 250 MPa.
There is no separate "A36H" grade recognized in the ASTM standard. The "H" is not part of the material grade; it denotes the product shape (H-beam). The correct nomenclature is "ASTM A36 H-Beam" or "ASTM A36 Wide Flange Beam." The "H" refers to the cross-section. Similarly, one would refer to an "A36 Channel" or "A36 Angle." The material standard (A36) remains the same.