Mammoth Uncensored Word List:
27 words ending with hs, 15 letters long

autolithographs autoradiographs chemoautotrophs ducentillionths duodecillionths encephalographs farthingsworths halfpennyworths microbarographs millinillionths myocardiographs photoautotrophs phototelegraphs plethysmographs pyrophotographs quadrilliardths quintilliardths radioautographs radiotelegraphs roentgenographs sedecilliardths shillingsworths telephotographs tredecillionths uncentillionths undecilliardths vigintillionths