lo Jan., 1 91 2.] 



Farm BlacksmiiJiing. 



=53 



The ordinary method of making a bolt in a black.smith's fire is, as 

 previously stated, to wrap a piece of square or flat iron around a circular 

 bar. Now, as the heads are to be made to fixed sizes, the size of the bar 

 used for forming the head requires to be carefully selected so as to make 

 the bolt with a minimum of labour. The following table is compiled to 

 enable the maker to at once select the most suitable size for bolts ranging 

 from \ in. to i in : — - 



T.AJBLE OF SIZE OF IRON FOR BOLT HEADS, WITH FINISHED DIMENSIONS 



OF HEAD. 



Diameter of bolt 

 Size of square iron for head 

 Width of head across the fiats 

 Depth of head 



1 

 i 

 If 

 1 



The correct method of making the collar to fomi the head is to first 

 of all find out the length which will exactly encircle the round bar. Thus, 

 to the diameter of bolt, add the thickness of square bar and multiply the 

 sum by 3)-. The end of the square bar is now heated to bright red and 

 placed on the hardee at a distance from the heated end equal to the re- 

 quired length when it is cut about half-w^ay through, as shown at a in 

 Fig. 44, and then bent to b when it is broken off, and the circular bar 

 inserted and the ends knocked down as shown at c. 



The collar is now driven 



off and the round bar heated 



^ to redness and placed in the 



collar similar to d, and driven 

 45. BOLT-TOOL. do^yn on the top. The object 



is to swell the round bar slightly where it will be wasted by obtaining 



the wielding heat. By altering the position of the bolt from vertical to 



horizontal and resting the collar on the anvil, a blow struck on it tightens 



it so that it will not slip off in the fire 

 In welding, the head is struck 



sufficiently hard to crush the metal 



and so form a flat surface on oppo- 

 site sides. It is quickly turned at 



right angles and struck. By this 



means the square head is roughly 



formed ; and, at the same time, the 



weld is partly made. To complete 



the welding and to obtain correct 



shape a bolt-tool (Fig. 45) or fork- 

 tool (Fig. 46) is required. 



When a bolt-tool is used, the bolt* 



is immediately placed through the 



hole and the square hole of the anvil, ^5. method of using a fork-tool 



and hammered down to the required 



depth, then removed, and again hammered on the sides. A pair of 



calipers should be previously set to the width of the head for testing the 



size. 



The fork-tool mnv be used for heading various sized bolts, and in that 



respect is a better tool than the bolt-tool, w'hich can only be used for one 



size, so that a set of such tools would be necessary. 



