M&B Engineering shares fell 11.19% to ₹265.10 after the company approved a ₹30 crore brownfield expansion to add 10,000 MTPA Heavy Structural Steel capacity at its Sanand plant. Capacity will rise to 22,000 MTPA by Q1 FY28. The company sees opportunities in data centres and high-rise construction, while IPO proceeds were used for capital expenditure and debt repayment.