Stove  Bolts Stove bolts (figure 3-82) are less precisely made than machine bolts. They are made with either flat or round  slotted  heads  and  may  have  threads  extending over the full length of the body, over part of the body, or  over  most  of  the  body.  They  are  generally  used with  square  nuts  and  applied  metal  to  metal,  wood  to wood,  or  wood  to  metal.  If  flatheaded,  they  are countersunk.  If  roundheaded,  they  are  drawn  flush  to the surface. Expansion Bolt An expansion bolt (figure 3-82) is a bolt used in conjunction   with   an   expansion   shield   to   provide anchorage in substances in which a threaded fastener alone is useless. The shield, or expansion anchor, is inserted in a predrilled hole and expands when the bolt  is  driven  into  it.  It  becomes  wedged  firmly  in  the hole,  providing  a  secure  base  for  the  grip  of  the fastener. Toggle  Bolts A  toggle  bolt  (figure  3-82)  is  a  machine  screw with a spring-action, wing-head nut that folds back as the entire assembly is pushed through a prepared hole in a hollow wall. The wing head then springs open inside the wall cavity. As the screw is tightened, the wing head is drawn against the inside surface of the finished   wall   material.   Spring-action,   wing-head toggle  bolts  are  available  in  a  variety  of  machine screw  combinations.  Common  sizes  range  from  1/8 inch to 3/8 inch in diameter and 2 inches to 6 inches in length.  They  are  particularly  useful  with  sheetrock wall  surfaces. Molly Bolt The   molly   bolt   or   molly   expansion   anchor (figure 3-82) is used to fasten small cabinets, towel bars, drapery hangers, mirrors, electrical fixtures, and other  lightweight  items  to  hollow  walls.  It  is  inserted in a prepared hole. Prongs on the outside of the shield grip  the  wall  surfaces  to  prevent  the  shield  from turning as the anchor screw is being driven. As the screw  is  tightened,  the  shield  spreads  and  flattens against the interior of the wall. Various sizes of screw anchors can be used in hollow walls 1/8 inch to 1 3/4 inches thick. Figure  3-83.-Driftpin  (driftbolt). Driftpins Driftpins are long, heavy, threadless bolts used to hold  heavy  pieces  of  timber  together  (figure  3-83). They have heads that vary in diameter from 1/2 to 1 inch and in length from 18 to 26 inches. The term “driftpin”  is  almost  universally  used  in  practice. However,  for  supply  purposes,  the  correct  designation is  driftbolt. To  use  the  driftpin,  you  make  a  hole  slightly smaller than the diameter of the pin in the timber. The pin is driven into the hole and is held in place by the compression action of the wood fibers. CORRUGATED  FASTENERS The corrugated fastener is one of the many means by  which  joints  and  splices  are  fastened  in  small timber and boards. It is used particularly in the miter joint.  Corrugated  fasteners  are  made  of  18-  to 22-gauge  sheet  metal  with  alternate  ridges  and grooves; the ridges vary from 3/16 to 5/ 16 inch, center to  center.  One  end  is  cut  square;  the  other  end  is sharpened  with  beveled  edges.  There  are  two  types  of corrugated   fasteners: one with the ridges running parallel (figure 3-84, view A); the other with ridges running at a slight angle to one another (figure 3-84, view B), The latter type has a tendency to compress the material since the ridges and grooves are closer at the top than at the bottom. These fasteners are made in  several  different  lengths  and  widths.  The  width varies from 5/8 to 1 1/8 inches; the length varies from 1/4  to  3/4  inch.  The  fasteners  also  are  made  with different  numbers  of  ridges,  ranging  from  three  to  six ridges per fastener. Corrugated fasteners are used in a number of ways—to fasten parallel boards together, as in fastening tabletops; to make any type of joint; and as a substitute for nails where nails may split the timber.  In  small  timber,  corrugated  fasteners  have greater  holding  power  than  nails.  The  proper  method of using the fasteners is shown in figure 3-84. ADHESIVES Seabees  use  many  different  types  of  adhesives  in various phases of their construction projects. Glues 3-60