Skip Douglas , Feb 20, 2005; 08:12 a.m.
Most cameras have a 1/4-20 (1/4" diameter, 20 threads per inch) socket for attachment to a tripod. This is a VERY common American thread size and will be found in any American hardware store, Wal-Mart, etc.
One caution - make sure that the bolt that you get is not too long. You do NOT want the bolt to bottom out in the camera's threaded socket. If you tighten a bolt which is bottomed out in the camera's socket you risk damage to the camera.