DTH Drill Bits (Page 2 of 2)

Flat, Concave or Convex Face

Face profile is the first call after diameter. A flat-face bit is planar across the front with multiple flushing holes, so impact loads all the buttons uniformly — the most stable, straightest-drilling profile, at a slightly slower penetration rate than a convex bit. A convex-face bit is slightly domed for fast penetration and balanced wear in medium to hard rock while still holding hole alignment. A concave-face bit is recessed into a shallow dish, which favors hole straightness and flushing of cuttings. Every diameter on this page is built in all three.

Match the Bit to Your Hammer Shank

DTH bits are not brand-specific. They are ordered by shank designation and head diameter, both industry standards, so the bit follows the hammer, not the badge on it. Confirm your shank family, then pick the diameter.

Filter the grid above by diameter and face profile, or call with your hammer model and we will confirm the shank before you buy.

Carbide, Flushing and Bit Life

Every bit here is set with ballistic tungsten carbide inserts laid out to load the face evenly and hold gauge. Flushing holes across the face clear crushed rock on the hammer’s exhaust air; the convex bits use optimized flushing channels to cut regrinding, which is the fastest way to burn up a face. Each bit is precision-machined to its shank so piston energy goes into the rock rather than the joint. Size the air compressor to the hammer’s CFM and working pressure — the hammer guide covers that by size class.

The Rest of the Drill String

DTH is one of several systems we stock. On the top-hammer side, build the string with extension and drifter rods, thread adapters and couplings, and striking bars and shanked rods. For shallower holes a handheld pneumatic rock drill costs far less to run than a DTH rig, and odds and ends like the drill steel unplugger sit under miscellaneous.

Common Questions

What is a concave drill bit? A concave-face DTH bit has a dished, recessed center instead of a flat or domed front. The recess helps the bit track straight and flush cuttings, so crews reach for it when hole direction matters. It is stocked in every size from 3 to 15 in., including the 8 in. concave bit.

Concave, convex or flat face — which one drills faster? Convex is the fast profile in medium to hard rock. Flat face gives up a little penetration rate for uniform impact across the buttons and excellent hole direction control. Concave is the profile to reach for when hole straightness and flushing matter most. In broken or layered ground, hole control usually pays better than raw speed.

Are DTH bits interchangeable between brands? Yes, by shank. A bit is specified by shank designation — DHD35, DHD340, DHD360, DHD380, MC100 and MC120 on this page — and by head diameter, both industry standards. Match the shank family your DTH hammer uses and the bit fits, whoever built the hammer.

What is the difference between DTH bits and rock drill bits? A DTH bit threads onto a hammer that travels down the hole with it, so impact never fades with depth. A top-hammer bit sits at the end of a steel string with the percussion up at the drill. Two different systems — choosing drill steel and rock drill bits sorts out which one you are in.

When will my order ship? We ship out of Denver. In-stock orders placed by 4 PM ET leave the same day; anything not on the shelf ships as soon as it lands. Ask us to confirm availability on a particular dth drill bits if the schedule is tight.