DTH Drill Bits

Request a Quote

Website: http://rockdrilltool-en.com/dth-drill-bits-1-1-3.html

Micro-piling

Quarrying

Water well drilling

DTH drill bits without skirt

Model	3.5"	4"	5"	6"	8"	10"
Length	181mm	209mm	260mm	308mm	350mm	375mm
Diameter	54.6mm	65mm	84mm	101.5mm	128.5mm	165mm
No. of splines	8	8	8	8	10	10
Recommended hole size	90-110mm	105-130mm	135-152mm	155-190mm	203-254mm	245-305mm
Shank model	DHD3.5A	DHD340A	DHD350A	DHD360A	DHD380A	NUMA100A

Model	4''	5''	6''	8''
Length	228mm	260mm	231mm	329mm
Diameter	62mm	82.5mm	106.5mm	128.5mm
No. of splines	12	12	12	12
Recommended hole size	105-130mm	135-152mm	155-190mm	203-254mm
Shank model	MISSION40	MISSION50	MISSION60	MISSION80

Model	4''	5''	6''	8''
Length	279.5mm	240mm	253mm	331mm
Diameter	68mm	88.5mm	106mm	136mm
No. of splines	10	12	12	16
Recommended hole size	105-130mm	135-152mm	155-190mm	203-254mm
Shank model	QL40A	QL50A	QL60A	QL80A

Model	4''	5''	6''	8''	10''	12''
Length	260mm	258mm	324mm	321mm	355.8mm	470mm
Diameter	67mm	82.5mm	102mm	118mm	164.5mm	185.5mm
No. of splines	8	8	8	8	8	8
Recommended hole size	105-130mm	135-152mm	155-190mm	203-254mm	245-305mm	305-400mm
Shank model	SD4A	SD5A	SD6A	SD8A	SD10A	SD12A

DTH drill bits with skirt

Model	4''	5''	6''	8''	10''	12''
Length, L	260mm	258mm	324mm	321mm	355.8mm	470mm
Diameter,Ø	67mm	82.5mm	102mm	118mm	164.5mm	185.5mm
Length, L1	54mm	54.5mm	53mm	57mm	60.3mm	48mm
Diameter, Ø1	26mm	32mm	36.4mm	41mm	56mm	63.5mm
No. of splines	8	8	8	8	8	8
Recommended hole size	105-130mm	135-152mm	155-190mm	203-254mm	245-305mm	305-400mm
Shank model	SD4	SD5	SD6	SD8	SD10	SD12

Model	3.5''	4''	5''	6''	8''	12''
Length, L	181mm	209mm	260mm	308mm	350mm	375mm
Diameter,Ø	54.6mm	65mm	84mm	101.5mm	128.5mm	165mm
Length, L1	54.6mm	59mm	56mm	55mm	51mm	52mm
Diameter, Ø1	24.5mm	27mm	35mm	38mm	50.6mm	63.5mm
No. of splines	8	8	8	8	10	10
Recommended hole size	90-110mm	105-130mm	135-152mm	155-190mm	203-254mm	245-305mm
Shank model	DHD3.5	DHD340	DHD350	DHD360	DHD380	DHD112

Model	4''	5''	6''	8''
Length, L	279.5mm	240mm	253mm	331mm
Diameter,Ø	68mm	88.5mm	106mm	136mm
Length, L1	59mm	52mm	59mm	54mm
Diameter, Ø1	32mm	38.5mm	46mm	54.6mm
No. of splines	10	12	12	16
Recommended hole size	105-130mm	135-152mm	155-190mm	203-254mm
Shank model	QL40	QL50	QL60	QL80

How should the appropriate DTH drill bit be selected for a specific project?

Bit selection should be evaluated based on three key aspects: formation characteristics, required hole depth, hole diameter. General recommendations:

Extremely hard formations: Use large-diameter domed button bits, preferably with double-row button configuration
Very hard formations: Use domed button bits with a flat face design.
Medium to hard formations with uniform rock layers: Use domed button bits with a concave face design.
Medium to soft formations: Use edge domed buttons combined with center sharp or fully pointed buttons, preferably with a convex face design.

What is an “oversized drill bit”?

An oversized drill bit refers to a drill bit whose diameter or design exceeds the standard specifications or recommended operating limits for a given DTH hammer. Such bits fall outside our standard quality warranty scope. We generally classify oversized drill bits into the following two categories:

Customer-specified special-purpose bits: When a drill bit is customized for an unclear application or highly specific operating conditions, it is manufactured strictly in accordance with the customer''s drawings, material specifications, and process requirements. In such cases, no performance or service-life guarantees can be provided.
Excessive bit diameter: Drill bits with excessive diameters significantly increase the torque load at the connection between the bit and the hammer. This may exceed the structural limits of the bit shank, potentially leading to bit body cracking, fracture, or other unpredictable failures.

Is there a warranty if the carbide buttons break?

Carbide button breakage alone is not covered under the standard warranty. Carbide buttons are extremely hard and are designed to crush hard rock under normal drilling conditions without fracturing. However, button breakage may occur when the carbide impacts materials of similar or higher hardness, such as alloy steel objects left in the hole. Before drilling, ensure that no alloy steel debris or foreign metal objects are present in the target drilling area. During drilling, carbide button breakage may be indicated by abnormal impact noise. If such noise is detected, drilling should be stopped immediately and the hole bottom cleaned to prevent secondary damage to other buttons.