When we talk about button bits (or rock button bits), we’re referring to bit types that use multiple hard-faced inserts — “buttons” — typically tungsten carbide or similar high-hardness materials, embedded into the bit face to fracture rock primarily via impact (in percussion or DTH drilling) rather than just shearing or gouging.

Roller Bits: How They Work & Where They Fit

Roller bits (or roller-cone bits) feature two or three cones that roll and rotate as the drill string turns. Each cone has teeth or inserts, and the combined action crushes, chips or gouges the rock. Here are some core features:

The principle is crushing + gouging rather than pure fracturing.

They often perform well in formations where the rock is of medium hardness or when the formation can be crushed or chipped by a rolling action.

Because the cones rotate, there are bearings, seals, etc — adding complexity, potential wear points, and maintenance.

When roller bits are appropriate:

Medium-hard formations, mixed rock formations.

Situations where wear and abrasion are moderate.

Projects where the equipment and rigs are set up for rotary drilling.

Limitations of roller bits:

In excessively hard or highly abrasive rock the cone teeth/inserts may wear very quickly.

The crushing/gouging mechanism may be slower or less efficient than more aggressive impact/fracture methods in some applications.

Maintenance (bearings, seals) is more of a concern.

Button Bits / Rock Button Bits: How They Work & Where They Fit

Now let’s turn our attention to button bits. Their design is different and quite suited to rock-drilling conditions. Key aspects:

These bits are built for drilling hard or abrasive rock using impact (for example via DTH hammers) or high-energy percussive action rather than purely rotational cutting. One source notes: “Button drill bit is suitable for dry and wet drilling of medium hard and hard rocks.”

The “buttons” (tungsten carbide inserts) are arranged on the face to maximise rock fracturing, good flushing, and long service life in tough formations.

Because they’re designed for rock conditions, with strong metallurgy, robust body and good flushing design, they tend to be more rugged under challenging conditions.

When button bits are appropriate:

Hard rock formations, highly abrasive strata, or where impact drilling (e.g., DTH) is used.

Projects requiring deep or large holes in rock, where bit life is critical, and downtime is costly.

When rig is set up for high-impact/pneumatic or hydraulic drilling rather than purely conventional rotary.

Limitations of button bits:

In softer formations the aggressive face may cause over-break, inefficient drilling or unnecessary wear.

Might require rig/hole setup optimised for impact or DTH rather than simple rotary.

Up-front cost may be higher (but the lifecycle cost could be lower in the right conditions).

Case Example: Hard Rock Scenario

Imagine you’re drilling in a quarry setup with very hard, abrasive rock. You’ve tried roller bits and found that after only short intervals the inserts are worn out, penetration drops, and you have frequent bit changes. In this scenario shifting to rock button bits—with strong button design, robust bit body, optimised flushing for chip removal—makes sense.

The choice between roller bits and button bits (rock button bits) depends heavily on your geological conditions, drilling method, rig capability, and cost / bit-life trade-off. Button bits shine in tough, abrasive rock under impact drilling; roller bits can be very effective in softer or moderate conditions. Matching the tool to the job is key to performance and cost-effectiveness.