An adjective glossed “awkward, hard” in Definitive Linguistic Notes (DLN) from 1959 derived from the root √SRAG (PE17/154). On a rejected page from these same notes it was glossed “being onerous, harsh”, but that form was marked through (PE17/172). Two other forms on the rejected page, hranye and hrane, may have had similar meanings but appear to have been abandoned. In notes from December 1959 (D59) it was given as hranga “stiff, awkward, difficult”, identical in meaning to hrai (PE17/185), but in DLN hrai(a)¹ was glossed “awkward, difficult” distinct from hranga.

Neo-Quenya: I believe that hranga means “hard” in both the sense “difficult” and “stiff, firm, resistant”, as opposed to hraia which is exclusively “difficult, awkward” and has no implication of physical hardness; see that entry for discussion.