METAL WORKING MACHINES-NAMELY, DRILLING MACHINES, MILLING MACHINES, BORING MACHINES, REAMING MACHINES, PIPE-THREADING MACHINES, COMBINED MILLING AND CENTER-DRILLING MACHINES, COMBINED MILLING, DRILLING, AND TAPPING MACHINES, COMBINED MILLING AND SPINNING MACHINES, AND MULTIPLE OPERATION MACHINES FOR PERFORMING VARIOUS OPERATIONS SUCH AS DRILLING, CHAMFERING, REAMING, AND SAWING