He's been hanging around with a bunch of tough guys.
The rug is made of tough material.
I have a tough constitution, and my profession taught me how to compete against long odds and big obstacles. —Lance Armstrong, It's Not About The Bike, (2000) 2001
… Pelletreau had firsthand experience in dealing with Israelis as well as with Arabs and had a reputation for being bold, analytical, and tough as nails. —Robert D. Kaplan, The Arabists, 1993
He had on the other hand to preserve his own reputation as a tough D.A. who dealt handily with the criminal classes. —E. L. Doctorow, Ragtime, (1974) 1975
… this wiry, tough, frenetic Algerian with the beneficent smile, who could vault over the bar and stiff-arm a drunk out into the night in less time than it takes to say Edgar Poe, and return, bland as butter, to take up where he left off … —William Styron, “The Paris Review,” August 1953, in William Styron, This Quiet Dust And Other Writings, (1953) 1982
Summer in New York is coasting the dairy aisle at Safeway. … It's finding the spot in a subway car where the vent blows strongest and staying there past your stop, toughing it out when the “excuse me, ladies and gentlemen” hard-luck stories blow through. —Guy Trebay, Village Voice, 30 July 1991
… they were toughing it out with the help of the greatest ally a macho young cop ever had, booze. —Joseph Wambaugh, Lines and Shadows, 1984