Stock photography, photos: Field of Bolts Stock photos of This is a grid of bolt heads from an old steam locomotive. The pattern is nearly regular. Strong side-lighting adds character to the image. Can easily be rotated to a vertical. Colour but object was painted glossy black, so the rsult in nearly black-and-white. Photograph: © Pat Croteau Click for a larger image and more information Keywords associated with this stock photo: locomotive, train, steam engine, vintage, antique, old, cast iron, machinery, bolt, screw