On February 18, 2012, at 1115 eastern standard time, a Cessna 182A, N20DE, sustained substantial damage when the left wheel separated from the left main landing gear during landing roll at the Harry Clever Field Airport (PHD), New Philadelphia, Ohio. The left wing sustained substantial damage when it struck the ground. The pilot and two passengers were not injured. The airplane was registered to and operated by E & S Aircraft, Inc., under the provisions of the 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed at the time of the accident, and no flight plan was filed. The airplane departed Richard Downing Airport (I40), Coshocton, Ohio, at 1100. The pilot reported that the landing was normal, but during the landing roll as the airplane was turning onto the taxiway, the left wheel separated from the landing gear. The examination of the airplane revealed that the four bolts that attached the wheel to the landing gear were broken. The National Transportation Safety Board's Materials laboratory examined the four fractured bolts. Two bolts were smaller in diameter. The fracture surfaces had a uniform matte-gray rough appearance consistent with ductile overstress fractures under tension loads. The two larger diameter bolts were bent in the shank area. Fracture surfaces on both bolts showed matte-gray features mixed with areas of post fracture damage. All features were consistent with ductile overstress fractures under off-axis loading. The pilot reported that the airplane was converted to a tailwheel airplane per a supplemental type certificate, and that it was equipped with tundra tires. The airplane was routinely landed off runways on sandbars, strip mines, and fields. The pilot reported that installing new bolts could have prevented the accident from occurring.