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12. Forging a pin for a D-shackle

Material. Hand length of 16-mm round bar (about 1200 mm); 8-mm square section or 10-mm round about 200 mm in length or a hand length.

Additional tools. 8-mm top and bottom fullers; slot punch with end 16 x 3 mm; 16-mm top and bottom swages; bolster plate; hot set.


Slightly upset one end of the 16-mm bar for a length of about 40 mm (Fig. 89A) and slightly fuller as in Job 9 but about 35 mm from the end (Fig. 89C). Forge a ring as in Job 9 to fit the 16-mm bar. Position ring in lightly fullered groove and weld into position with light hammer blows all round. If necessary, round the shank back to its original size beneath the ring so that it will fit a 16-mm hole in the bolster plate. Also, if required, reheat the pin and place it into the bolster plate and square up the shoulder, as in Fie. 90.

Reheat to a yellow heat and fuller a groove on the short end but close to the ring (Fig. 89E). Fuller to a square section first, then fuller the corners to give an octagonal section. This octagonal section should be about 10 mm thick. Take a near-welding heat on the remaining upset and flatten until about 8 mm thick, allowing the metal to spread sideways (Fig. 91). Reheat the head and round up the flattened end (Fig. 92). Heat again and punch an 8-mm hole in the centre of this rounded portion. Next finish the eye as for the hook in Job 10.

Mark off from the underside of the collar a length equal to the distance across the eyes of the D shackle plus 3 mm. This will be the end of a slot hole to be punched. From this mark measure 35 mm and cut off with a sharp hot set or hot chisel. Cut all around the job and this will leave a chamfered end. Reheat and place in a 16-mm bottom swage and punch a slot hole (Fig. 93), punching from both sides and using a little coal dust as 

in Job 10. This punching will cause a little swelling of the metal. Correct this by first using the 16-mm top and bottom swages and then lightly repunching the hole. Any additional swelling can be corrected by either rasping while the pin is hot or filing it when cold. Make sure that the whole job is straight and a good fit in the shackle eyes.

Agricultural engineering in development


Agricultural engineering in development


Agricultural engineering in development


Agricultural engineering in development


A simple cotter pin can be made by cutting off a 50-mm length of 1.5-mm steel sheet 16 mm wide. This is wrapped around an 8-mm diameter-rod, bending carefully at the centre of the flat strip. When bent into a U shape, grip the strip in the vice just below the 8-mm rod and squeeze in the vice jaws to bring the sides together, leaving a neat eye. Remove the rod and file the cotter if necessary to make it fit. Chamfer the ends and spring the ends apart slightly. This cotter will retain the shackle pin in the shackle eye (Fig. 94).

Agricultural engineering in development


Agricultural engineering in development


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