How do you drill through a 10.9 bolt?

To drill through a 10.9 bolt, first, secure the bolt in a vice or clamp to prevent movement. Use a cobalt or carbide drill bit, as these materials are better suited for high-strength steel. Start with a smaller pilot hole to guide the larger bit, and apply cutting fluid to reduce heat and increase drill life. Gradually increase the drill size until you reach the desired diameter, ensuring to maintain steady pressure and avoid overheating.