When sourcing a manual bar cutter, the most critical factor is the maximum cutting capacity, typically ranging from 6mm to 32mm for reinforced steel bars (rebar). You must verify the blade material, prioritizing high-strength forged alloy steel or T10 tool steel with a hardness rating of HRC 55-60 to ensure longevity. Additionally, evaluate the leverage design; a longer handle or a multi-linkage mechanism significantly reduces the physical effort required by the operator, enhancing workplace efficiency.