The Journal of the Department of Agriculture, Victoria . it would gradually become smaller as the distance from theend increased, until the original diameter of the bolt is reached, whichwould be where the heat does not rise sufficiently high to assume the redcolour. If the plain bar be long enough to conveniently hold in the handwithout burning it, the best means of upsetting it is to catch hold of thecold end and hold it in a vertical position. By repeatedly raising it toa good height and bringing the heated end down with as much force aspossible, it will become enlarged. In most cases, the
The Journal of the Department of Agriculture, Victoria . it would gradually become smaller as the distance from theend increased, until the original diameter of the bolt is reached, whichwould be where the heat does not rise sufficiently high to assume the redcolour. If the plain bar be long enough to conveniently hold in the handwithout burning it, the best means of upsetting it is to catch hold of thecold end and hold it in a vertical position. By repeatedly raising it toa good height and bringing the heated end down with as much force aspossible, it will become enlarged. In most cases, the bar will bend beforebeing sufficiently upset, but it can be straightened and the upsetting pro-ceeded with. To form the scarf, the best plan is to follow each successive stepshown in Fig. 47, where a shows the bar upset, b with the end bent soas to be conveniently struck with the hand-hammer in the direction andposition of the arrow, whilst c shows the shape made with the hammer,as well as the fuller in its place tO receive the first blow. As each blow. M 47. LENGTHENING BOLT. a. Bar upset. 6. End bent tor striking with hammer. c. Sliape made with hammer. Fullerin position to receive the first blow. d. Effect of using fuller. e and /. Correct position forhammering. is delivered, the fuller is moved slightly forward, leaving in its trail asuccession of little steps as shown at d. It should always be the objectof the operator to obtain the shape shown, for a bad weld is sure to followa badly formed scarf. Particular attention should be paid also to the manner in which thepieces are laid together; e and / show the correct position previous tohammering. For welding small iron, the hand-hammer is heavy enough,but the blows should be delivered as quickly as possible so that the unionis made complete before the temperature has fallen below the weldingpoint. If it is noticed that the weld is only partially made, then thework should be returned immediately to the fire and again raised t
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectagricul, bookyear1902
