I apologize for any confusion, but it seems like you are looking for black oxide square neck dome head plow bolts and plow bolt nuts in various grades (Grade 8, 8.8, 10.9, and 12.9).Plow bolts, also known as plough bolts, are commonly used in applications where a secure and reliable connection is required, such as attaching a cutting edge or plow to machinery or construction equipment. The square neck helps to prevent rotation and ensures a tight fit.The dome head design provides a smooth surface, minimizing the risk of damage to nearby objects and reducing the risk of injury for operators. The black oxide finish enhances corrosion resistance and provides a sleek appearance.In terms of grade, the higher the grade, the greater the tensile strength of the bolts. Grade 8, 8.8, 10.9, and 12.9 indicate different levels of strength and durability, with Grade 12.9 being the highest.Plow bolt nuts are used in conjunction with the plow bolts to secure them in place. They are typically hex nuts, designed to provide a strong and secure fastening.If you have specific requirements for black oxide square neck dome head plow bolts and plow bolt nuts in different grades, please let me know, and I will be happy to assist you further.