Drill Bits

Overview

About this part

Drill bits are consumables in coal mining: roof-bolting bits for installing ground support, tricone or PDC blasthole bits for surface mine overburden, and conical picks for continuous miner and roadheader cutting drums. Bit life is measured in meters drilled, holes drilled, or tons cut, and is benchmarked across suppliers as cost per meter or cost per ton. Bit grade selection balances upfront cost against in-service life and penetration rate.

Compatibility

Compatible Equipment

Mining Drill Bits

Materials

Material Options

Tungsten carbide button: Standard cutting element. Grade and geometry selected to match formation hardness.
Polycrystalline diamond: PDC, used in blasthole drilling on softer formations. Higher cost, longer life.
Alloy steel body: Forged alloy steel body holding the carbide inserts.
Brazed carbide block: Used in conical picks for continuous miner cutting heads.

Specifications

Technical Specifications

Drill Bits
Specification	Value	Unit
Bit Types	Roof bolt, tricone, PDC, conical pick
Diameter Range	25–311	mm
Shank Types	Hex, square, API regular, conical
Cutting Element	Tungsten carbide button, PDC

Wear behavior

Wear Factors

Formation compressive strength
Formation abrasiveness (silica content)
Drilling parameters (weight on bit, rotary speed)
Flushing medium and rate
Bit body fatigue

Replacement

Replacement Notes

Bits are run to end-of-life as defined by either gauge loss, button breakage, or unacceptable penetration rate. Surface blasthole operations track meters per bit and cost per meter. Continuous miner pick replacement is typically a planned activity at shift end based on observed wear.

Related Equipment

Mining drill bit / cutter

Mining Drill Bits

Rock drill bits and cutter heads for coal mining roof bolting, surface blasthole drilling, and continuous miner cutting drums.

Consumable Coal, sandstone, shale, mudstone roof and floor rocks

Frequently Asked

FAQ

Carbide button vs PDC blasthole bits — which is right for coal mine overburden?

Carbide button bits suit hard, abrasive overburden with moderate rotary speeds. PDC bits suit softer overburden and shallower formations and run at higher rotary speeds with lower weight-on-bit. PDC bits cost more but can deliver lower cost per meter where formation conditions suit them.

How are continuous miner picks specified?

Picks are specified by attachment system (radial conical, rotating conical, fixed), carbide grade for the formation, and dimensional compatibility with the cutting drum. Picks are usually run as a set across the drum; full sets are replaced together to maintain even cutting.

Why does flushing matter for bit life?

Inadequate flushing leaves cuttings in the hole, which are reground by the bit. Regrinding wastes energy, accelerates bit wear, and reduces penetration rate. Adequate flushing — at the correct flow rate for the medium — gives a clean hole and longer bit life.

How is bit performance benchmarked?

Bit performance is measured as cost per meter drilled (surface blasthole and roof bolting) or cost per ton cut (continuous miner picks). Tracking these metrics by supplier and bit grade builds a procurement evidence base. Bit cost alone is misleading without service life.