Diamond core drill bits can be either laser welded or silver brazed. Silver brazed diamond core drill bits can only be used in wet drilling. If they are used in dry drilling, their diamond segments may break off from their steel tube and may cause security issues.
Laser welded diamond core drill bits can be used in both wet drilling and dry drilling, and are now more popular. However, not all materials are suitable to be drilled dryly. If very hard materials, e.g., reinforced concrete, are drilled without water, the excessive heat generated may cause the diamonds on the core bit to become blunt, and then lead to poor drilling performance.