MODERN BLACKSMITHING 185 



Water or oil should be kept on the iron or steel that 

 is being turned. It keeps the point of the tool from 

 getting hot when heavy chips are taken, and it makes 

 a smoother job when the smoothing tool is used. 

 There is no need to use either water or oil when turn- 

 ing cast iron. 



The tempering of lathe tools is a very particular 

 piece of work, varying considerable with the kind of 

 steel used and the nature of the work to be done. For 

 slow heavy turning the tool must not be too hard, else 

 it would break ; while for light swift turning it should 

 be quite hard. For water tempering the temper color 

 varies from a dark blue to a very light straw color, 

 depending, as I have said before, on the nature of the 

 work to be done. 



By way of illustration of a piece of work that repre- 

 sents a number of lathe combinations, I will take the 

 fitting of a saw shaft for our common wood saws. First 

 place the balance wheel in the lathe chuck, being sure 

 to get it in the center, so that when the hole is drilled 

 in the wheel it will be in the exact center. Take a 

 drill a sixteenth of an inch smaller than the hole to be 

 made, and drill out the hole. Use the inside boring 

 tool to make the hole the desired size. Turn a smooth 

 face on the hub of the wheel where it comes against 

 the box; then the wheel is ready for the key seat. To 

 cut the key seat in the wheel use a key-seat chisel the " 

 same size as the milling wheel used to cut the key seat 

 in the shaft. 



Next take one of the saw collars; put it in the chuck, 

 being careful to get this in the center also, with the 



