patches on boilers. The patch is countersunk for the cone head, and boiler shell tapped for bolt thread. The square head is knocked off after bolt is screwed in place. Coupling Bolt Eolts for shaft couplings are finished all over and must be a close fit in the hole reamed in the two flanges of the coupling, so that the sections shall be rigidly secured together. Expansion Bolt-In attaching parts to brick, stone or concrete walls and floors, expansion bolts are frequently employed. The "Star" bolt in the illustration has an internally threaded, split sleeve which is slipped into a hole made in the wall and then expanded by running in the screw. The projections on the surface of the shell, and the fact that the hole receiving it is made larger at the rear, assure the device holding fast when the expander is in place. 411 Eye Bridge or Roof Sink Track U F H D E F Large Round Head - Square Head - Round Head, Square Shank Key Head - Tee Head - Button Head · Concave Head Reverse Key Head - Large Key Head. T-Head Planer Bolt Tap Bolt Tap bolts are usually threaded the full length of the body, which is not machined prior to running on the die. Only the point and the under side of the head are finished. They are not hardened and are used as a rule for the rougher classes of machine work. The heads are the same width as machine bolt heads. T-Head Planer Bolt- A bolt with a T-head having oblique ends which may be dropped into the T-slot of a planer and locked by giving it a quarter turn, until the sloping ends strike against the sides of the slot. Commonly employed for holding work on the planer table. Bolt Cutter - Machine for threading bolts, cutting threads on them. Machine for upsetting the bolt body to form the Bolt Header head. Bolster - A block sometimes called the die block, in which a punch press die is held. It is attached to the bed by bolts at either end. 0 Ф Bolster Boring and Turning Mill - Machine having a rotating horizontal table for the work with one or more stationary vertical tools for boring, turning or facing; a turret is often provided for holding a number of tools in one of the heads. Often called "vertical mill." Horizontal boring machines are not called "mills." |