Robert Sen. (bapt 1772 - 1839) was a joiner (and later victualler) and brother of William Marples Sen. Robert and his wife, Charlotte Foster (c.1775 - 1864), had three sons; Joseph; Robert (1807 - 1862); and Samuel (1803 - 18763). Robert Sen. died of 'natural decay' on 28 August 1839, aged 68, and was buried in the General Cemetery.

Robert Marples Jun. followed his father into joiners' tool manufacture. He was said to have started business in 1828; and until 1835 partnered his cousin, William Marples Jun. He relocated to Hermitage Street, where his tool firm employed 24 workmen by 1851.
A decade later 17 men, 4 boys, and 2 girls were employed. Hermitage Works produced a variety of woodworking tools, including a version of William Marples & Sons' metallic-framed brace, which Robert registered in 1857. These braces were stamped coincidentally, 'Ultimatum Brass Framed Brace' (Eaton, 1989).

Robert Marples died, 'after a long and painful illness', on 24 March (aged 54). He was buried in the General Cemetery and left under £3,000. The business passed to his only son, Henry Dixon Marples (1840 - 1920), who had reached his majority. Robert Marples & Son enjoyed modest success; 15 men and three girls were employed in 1871; a number that had increased to 19 men, four boys and two girls by 1881. The firm became a private limited company in 1911, with £5,000 capital, and with H. D. Marples and his son, Robert Henry Marples (1871 - 1954) as directors. Marples' 'HERMIT' trade mark dated from 1887. It also had a range of marks denoting quality; Special Quality, 'Robert Marples'; 1st Quality, 'H. D. Dixon'; 2nd 'Henry Dixon', 3rd 'Robert Henry'; and Common Quality, Henry Greaves' (who may have been Robert's brother-in-law). Eaton (1989) has detected a rivalry in these marks with those of William Marples & Son.

By 1915, Marples' had relocated to Aizlewood Road. Henry D. Marples, of Brincliffe Gardens. died on 3 May 1920, leaving £420. He was buried in Ecclesall. The firm was apparently winding down and in the directory (1925) it was listed as a tool manufacturer (stores) in Valley Road, Heeley. It was struck off the register of companies in 1935. Robert Henry, of Wye View, Buxton Road, Bakewell, died on 21 April 1954, aged 83. He left £9,745.