Published February 3, 2026
The face design of a DTH button bit strongly affects penetration rate, hole straightness and bit life. Here is how the common designs compare.
Convex face
Convex bits center themselves in the hole and reduce deviation. Best for medium-hard, fairly uniform rock and for keeping holes straight.
Flat face
Flat-face bits resist button breakage in very hard, abrasive formations such as iron ore and basalt. They penetrate a little slower but last longer.
Concave face
Concave bits are the all-rounders: good button placement, even wear and reliable straightness across quarry and mining work.
Drop-center
Drop-center bits concentrate energy at the center for fast penetration in softer, broken or weathered ground.
Beyond face design, button shape (spherical vs ballistic) and carbide grade should match abrasiveness. Our team can help you pick the right bit for your formation.