Abstract: A machine for inserting terminal pins into a printed-circuit board under programmed control has a pin-insertion head which is charged with pins from a reciprocating shuttle that executes only one stroke in response to each pin-insertion operation. The head is charged with a pin from one of two passages in the shuttle at the end of each stroke while the other passage is being loaded with a pin ready for translation to the head to recharge it, during the next stroke. The machine further includes apparatus for feeding the pins from a pin storage means to the shuttle.