A A compressor is a tool for compressing air/gas; the working principle of a compressor is that if a gas in a closed space is reduced in volume, the gas will experience an increase in pressure. Here the compressor uses a piston that works back and forth in the cylinder to suck, press or release gas repeatedly. In carrying out compression, the gas must not leak through the gap between the piston wall and the cylinder that rub against each other. For this reason, a piston ring is used as a seal. At the time of this final assignment, a single-stage piston compressor will be designed with a capacity of 0.048 m3/min (8.10-4m3/sec) with a rotation of 1200 rpm and an outlet pressure of 7 bar (7.10' Pa). So from the calculation results obtained a piston diameter of 42 mm (0.042 m) and a drive rod length of 75 mm (0.075 m)