Din 7504, Self Drilling Screws Hexagonal Head, Technical Specification And Weight Count Chart Of Self Drilling Screws Hexagonal Head With Flange Type K Din 7504 K. At Capital Bolts Our primary focus is on providing high-quality products from many manufacturers. Capital Bolts & Hardware is a well-known name among the topmost suppliers and manufacturers of premium quality fasteners. Capital Bolts & Hardwares is a well-known name among the topmost suppliers and manufacturers of premium quality fasteners. It was founded by Mr. Ramprakash Nagpal in the year 1959, to meet the growing demand for quality products for fixings\' applications in the construction works, mechanical equipment, and household appliances. Over the past six decades, Capital Bolts & Hardwares has grown under the energetic leadership of 3 generations and evolved as a large scale company of premium fastening products. Quality checks and activity control at each stage are followed as a custom to ensure to deliver value to the customer.