It is not listed.

http://www.astm.org/Standards/B862.htm

http://www.astm.org/Standards/B861.htm

"Note 1—H grade material is identical to the corresponding numeric grade (that is, Grade 2H = Grade 2) except for the higher guaranteed minimum UTS, and may always be certified as meeting the requirements of its corresponding numeric grade. Grades 2H, 7H, 16H, and 26H are intended primarily for pressure vessel use.
The H grades were added in response to a user association request based on its study of over 5200 commercial Grade 2, 7, 16, and 26 test reports, where over 99 % met the 58 ksi minimum UTS."


I think that you should treat as unlisted material therefore better to stay out of this. You maybe noted that the use of this grade is not permited for Section I, Section III and Section IX.

Regards,