The pilot was landing a 1950 Cessna 170A on runway 3; a 5,500-foot-long, 100-foot-wide, asphalt runway. About 1,000 feet into the landing roll, the left main landing gear collapsed. The airplane initially veered left, then veered right, and came to rest in a grass area off the right side of the runway. During the landing, the left main landing gear and left wing sustained substantial damage. The pilot did not report the accident, but a maintenance facility notified the Federal Aviation Administration 12 days after the accident. The owner of the maintenance facility stated that four bolts, which secured the left main landing gear wheel to the strut, had sheared. The pilot subsequently stated that the bolts appeared to be "rusty." A request was made for the maintenance facility to have the bolts forwarded to the Safety Board's Materials Laboratory, Washington, D.C. for examination; however, the maintenance facility had already discarded the bolts while repairing the airplane. The airplane had been operated for approximately 40 hours, since its last annual inspection, which was performed about 2 months prior to the accident. The reported wind at the airport, about the time of the accident, was from 150 degrees at 4 knots.