Abstract: A butt clamp consists of two shoes slidably mounted within a sleeve. The shoes are joined by a bolt having a nut threaded onto one end thereof. Each shoe has suitable openings therein so that it can be affixed to a substrate of a section of countertop. The assembled clamp is used to join two sections of countertop where one shoe is affixed to one section and the other shoe is affixed to the other section. The sleeve aligns the two shoes and when the bolt and nut are tightened, the two shoes are pulled towards one another, thereby pulling the two sections towards one another until the two sections are joined. Additional clamps can be used on the same joint. Adhesive can be used in the joint if desired. When the clamps are used, the two sections of countertop can be joined in the field rather than at the manufacturing site. Presently after two sections of a countertop have been cut along a 45.degree. angle, part of the substrate of each section is machined out by a LOCKTITE machine.