This study evaluated efficient milling of maize grains using a TW-cyclone series hammer mill. The assessment was conducted using two maize varieties—Quality Protein Maize (QPM) and SAMMAZ 11—at two moisture levels (13.5% and 16.5%) and two rotor speeds (950 rpm and 1050 rpm). A factorial experimental design was employed, and statistical analysis was conducted using ANOVA and Duncan’s Multiple Range Test. Four output factors were analysed: throughput capacity, milling efficiency, fineness modulus, and estimated energy consumption. The results indicated that moisture content significantly influenced milling efficiency and fineness modulus, while rotor speed had a considerable effect on throughput capacity, fineness modulus, and energy consumption. The maximum throughput capacity of 152.9 kg/hr was achieved with QPM at a moisture content of 16.5% and a rotor speed of 1050 rpm. The SAMMAZ 11 variety produced the finest flour particles, with a fineness modulus of 2.76, under similar conditions. The highest milling efficiency, recorded at 80.79%, was observed with QPM at 13.5% moisture and a rotor speed of 1050 rpm. Conversely, the lowest projected energy consumption of 0.0564 kWh occurred with QPM at 13.5% moisture and a rotor speed of 950 rpm. Percentage contribution analysis revealed that rotor speed was the most influential factor affecting throughput capacity (97.84%), fineness modulus (75.47%), and estimated energy consumption (74.4%). In contrast, moisture content emerged as the most significant factor influencing milling efficiency (62.55%).