Drilled nuts are primarily used to securely assemble industrial products. Common issues include teeth not fitting tightly, the nut head breaking off when over-tightened, or poor teeth design leading to loose assembly, all of which fail to meet usage requirements due to quality precision issues. Drilled nuts are "quantity products," not handcrafted art pieces. The aim in mass production is to achieve high precision and stable quality at affordable prices for consumers. The precision of drilled nuts is typically 6g grade (Grade 2, with the American specification "IFI" being Grade 2A teeth), while coarse-threaded bolts for construction are 8g grade (Grade 3, with "IFI" being Grade 1A teeth). The value of drilled nuts is extremely important; there are examples in the world where poor quality drilled nuts have led to the bankruptcy of car factories, as well as instances of aircraft crashes and vehicle rollovers due to substandard nut quality.