Purpose: This research aims to analyse the influence of blanking clearance size on the burr development for mild steel sheet, brass and aluminium. The main reason for this research is estimating the burr size on blank parts. It is still significant since the quality of the products is determined by evaluating the amount of allowable burr in the parts. Design/methodology/approach: For the blanking process on the 3.00 mm thick sheets, various sizes of blanking clearance for a 20 mm diameter of the die opening are employed, as is the technique for obtaining the parts. Then the height of the burr on each product was measured using a micrometre and toolmaker microscope. The height of burr for each size of blanking clearance have been recorded and compared using a graph. Comparison made to identify which measure of blanking clearance and which type of material will produce a small size of burr. Findings: For mild steel, brass, and aluminium, blanking clearance 0.15 mm produced burr heights of 0.088 mm, 0.015 mm, and 0.024 mm, and blanking clearance 0.13 mm produced bur heights of 0.192 mm, 0.055 mm, and 0.046 mm, respectively. The brass had a lower burr height than mild steel and aluminium, according to the results. More significant blanking clearance (0.15 mm) produced a smaller size of burr compared to a smaller blanking clearance (0.13 mm). Practical implications: This study focuses on burr height rather than the wear of the punch and die cutting edge; burr height can affect punch and die sharpness. It also can guide practitioners in estimating blanking clearance and the burr height of mild steel, brass and aluminium. Originality/value: This paper demonstrates that the gap between the punch and die influences the burr height. The material strength also affects the burr height, with a high tensile strength resulting in a larger burr.