110 ANNUAL OF SCIENTIFIC DISCOVERT. 



Machine-made Nuts. Good nuts, which shall at the same time be 

 cheap, and machine-made, have long been a desideratum ; several in- 

 ventions have been recently brought out which finish and turn out 

 nuts much cheaper and better than any that are manufactured by 

 hand. The following description of one machine will serve as a type 

 of the others. 



A heated iron bar, about the width and thickness of the intended 

 nut is advanced over a die-box of the exact shape of the periphery of 

 the nut to be made. A die then descends, severs a blank from the bar, 

 and forces it into the die-box. The die is bored out precisely to the 

 same size as the- aperture required in the nut, and, as it carries the 

 blank along, forces it still enclosed in the box, against a cylindrical 

 punch, which punches out the hole, carrying the disk it severs, and 

 finally entering itself into the aperture in the die. This die, with the 

 nut now punched out, and upon the punch in front of it, still advances 

 until it brings the nut in contact with the face of another die, which 

 like itself fills the die-box, and commences to move in the same direc- 

 tion as the first die is travelling, but with a less velocity. The nut is 

 therefore submitted to powerful pressure between these two dies while 

 still on the punch, and all cracks incident to the cutting or punching 

 of it are thoroughly welded up, while the exterior of the nut is forced so 

 strongly into the moulded faces of the dies that, when discharged from 

 the machine, it is nearly equal in smoothness to a nut that has been 

 planed. Actual experiment has proved that the compression is an 

 essential part of the operation, and that nuts merely severed and 

 punched are not only rough in appearance, but are so filled with cracks 

 as to be unable to withstand the strain to which they must be sub- 

 jected. 



File j\Iacldnes. An improvement in file machines, presenting an 

 easy method of giving different amounts of feed to the carriage which 

 supports the blank at certain times firmly on its bed, while at others it 

 gives it free motion to adapt itself to the chisel, has also been patented. 

 Machines of this class have long occupied the attention of the inventor, 

 and have lately come into actual use ; good coarse files made by one 

 lately patented being in the possession of the Office. It does not ap- 

 pear, however, that any of them have, in the manufacture of fine files, 

 been able to compete with that exquisite sense of touch which is the 

 unfailing guide of the file cutter, and which, in many instances in this 

 branch of manufacture, puts the blind workman on even a better foot- 

 ing than his comrade who has full possession of his sight. Many of 

 these machines have apparatus which actually set the chisel by feeling. 

 Complication, however, must result from such a basis of action, and 

 the present successful machines perhaps owe their efficiency, in no 

 small degree, to the simplicity of movement which disregards inequali- 

 ties in the texture of the blank, and, while it may spoil some files, is 

 yet unfailing in its own power to produce, and does produce, a good 

 article whenever a blank approaching to perfection is submitted to its 

 action. 



Threading Wood Screws. -- Among the many improvements in ma- 



