A ‘HOOK-TOOL”  (handheld)
    OF 1850
SKILL REQUIRED IN THREADING
                                     1896  AMERICAN MACHINIST                      
                                             
                                             
     The base or bed of an engine, particularly a steamboat
  engine, was a “timber”; the long unwieldy “pitmans” were (and still are) made from a
  single spar bound with iron; valve and reach-rods,levers, and other minor parts were jobs for
  the carpenter and ship builder rather than for him whom we now call machinist.        
   Running a lathe in those days was not the  “cinch” that it afterward became; there were
  no slide rests and no feeds to “throw in” so that the lucky operator could start things moving
  and then go to sleep on a soap box. Turn- ing was accomplished with the “hook-tool,” two of
  which still occupy positions of safety (for the operator) if not of honor, under  
  the safe in Walter Renton’s office. He calls them his “relics of barbarism.”            
   The picture of one of these tools that was doing valiant service 60 or 70 years ago appears
  on this page in Fig. 1. To use it the lathesman settled the point of the hook into the rough
  surface of the T rest, held the long end  firmly upon his shoulder with one hand while
  with the other hand he tilted the downwardly projecting handle in such a way that the   
  lip of the tool was moved forward in a direction parallel with the axis of the work.  
   
          
           If the piece being turned was. good homogeneous iron,
  little difficulty would be experienced,    
  With a properly ground lip the tool would  
  almost feed itself forward until the angle
  of presentation became too great; when the
  heel or “hook” would have to be moved forward
  to get a fresh bite. The long end of the   
  tool must be held tightly down on the shoulder
  so that the workman could at all times feel
  the pressure, and woe betide the unlucky wight
  who let his attention waver. George Renton
  told me a story in which a ma- chinist whom
  he called “Charlie” was the hero and this particular
  tool the vil- han. It seems that Charlie was
  turning a piece of iron in a lathe that    
  stood before an open window on the Ferry   
  St. side of the build- ing. Either there   
  was a seam in the iron, or Charlie for an  
  instant forgot his re- sponsibilities, for
  the end of the tool suddenly flew up and fetched
  him a resounding thwack under the ear that nearly
  laid him out cold, after which it sailed   
  merrily ‘out of the window and landed among
  some kids that were playing in the street,
  scaring them into flight. It took some moments
  and much sympathy and ad- vice from his shopmates
  to restore Charlie’s equilibrium but when  
  his head had cleared sufficiently to allow
  him                                        
  -to navigate he went out into the street   
  to retrieve the                            
  Vol. 53, No. 22 1                          
                                             
  tool. As he stooped to pick it up a large  
  lady of Hibes nian extraction appeared suddenly
  from behind nearby tree and commenced to   
  belabor him unmerc fully with a horsehide  
  strap; calling him between b~ a “dirty spaljeen
  that c’uldn’t let the little chil play widout
  t’rowin’ t’ings at ‘um.” It required the corn, bined
  office and shop forces to effect an armistice.
  After a job was roughed out with the hook-tool
  th~                        
               latter was ex.i                            
  changed for a 1 o n g-h an d led square-nosed
  tool which would be pushed along the       
   top of the rest                            
  with the hand, reducing the humps to the   
  diameter of the hollows left by the hook-tool.
  Although this finish- ing tool was not quite
  so erratic in disposition as its predecessor
  it still required a firm hand and a skill born
  of long experience to do a creditable job.
      Threading was done with two tools made especially for
  the purpose. The first was a graver, having
  a single sharp point with which the lathesman
  would “start” the thread by a dexterous twist
  of the wrist, running up a turn or two on  
  the work. Here, too, only the skill of the
  practiced artisan would suffice, for there was
  nothing but the movement of his hand guided
  by his eye to establish the lead.          
                 When a partial thread of one or two turns  
  had been cut, the “chaser” was brought into’
  service. This would be a tool having several
  “teeth” of the exact shape and pitch of the
  required thread. The first turn or two cut
  by the graver served to start the forward  
  move- ment of the chaser and it            
  was up to the workman to continue the same
  relative rate of advance as he made pass   
  after pass over the work until the teeth   
  of the chaser had gotten suffi- ciently deep
  into the metal to guide itself. By the time the
  thread had been cut to half its depth the  
  chaser would of course be guided by its own
  accurately pitched teeth, not only in- suring
  the regularity of the threads but correct  
  the slight inaccuracy of the starting threads
  cut by the graver. Capscrews, bolts, studs,
  etc., were not then available as a commer- cial
  product, therefore the                     
                 making of these small but                  
  important items was a stock job to be followed
  up when- ever work ran slack, or inclement
  weather kept the workers indoors.          
      Blacksmithing was a fine art and not a few
  parts came, all finished and ready to take
  their place in the machine, from the anvil.
  The good machinist was also blacksmith,    
  carpenter, millwright andY pattern maker; not
  infrequently foundryman as well. The broad
  axe or the sledge; the plane and the bit-brace,
  or the ham-                                
                                             
  
  
Navigation Bar Placeholder
Page Title