In this work, a 20 kHz Titanium (Ti) ultrasonic waveguide system for nano-surface treatment was designed and fabricated. In the design process, finite element analysis using ANSYS software was performed to find optimal dimensions of the waveguide, which can raise energy efficiency. The obtained anti-resonance frequency for a Ti waveguide with a piezoelectric actuator was 20.0 kHz, which agreed well with the experimentally obtained value of 20.1 kHz (0.5% error). To test the system performance, chromium molybdenum steel (SCM) 435 specimens were tested. As a result, the reformed thickness was 30 µm. Additionally, hardness tests were performed and the hardness before the process was 14.0 Rockwell Hardness—C scale (HRC) and after the process was 20.5 HRC, which means 46% increase. Finally, friction coefficient was measured and the value was 0.1. Considering these result, the developed Ti ultrasonic machining equipment is thought to be effective in the nano-surface treatment process.