sheet piling vs sheet pile

sheet piling and sheet pile both are nouns.

Word	Noun	Adjective	Verb	Adverb
sheet piling	Yes	No	No	No
sheet pile	Yes	No	No	No

As nouns, sheet piling and sheet pile are synonyms defined as:

sheet piling and sheet pile: a pile in a row of piles driven side by side to retain earth or prevent seepage

Other synonyms of sheet piling include sheath pile.

sheet piling (noun)	sheet pile (noun)
a pile in a row of piles driven side by side to retain earth or prevent seepage	a pile in a row of piles driven side by side to retain earth or prevent seepage