<p>Orbital angular momentum (OAM) has been employed as a unique physical degree of freedom and has sparked attention in various domains owing to its unbounded helical phase index. Due to its importance in numerous applications, including high-capacity expansion and controlling the rotation speed of trapped particles, OAM’s scalability has always been a subject of study. As a result, there has been a growing focus on creating an arbitrary customisable OAM mode spectrum. Typically, coaxial superposition of many vortex beams produces the OAM spectrum, which could make the system more complex. Here, we present and experimentally demonstrate a technique that utilises a binary array of pinholes to create vortices in the coherent beam with a tunable OAM spectrum. The pinhole masks are fabricated using a lithographic technique followed by a wet etching method. We show that pinholes arranged in a spiral structure can convert a plane wave into a beam with a wide OAM spectrum. By altering the shape of the pinhole masks, this beam can be tuned to produce either a single pure OAM mode or multiple OAM modes. An interferometric system and the Fourier fringe analysis method experimentally confirm the presence of vortices and OAM modes in the beam.</p>