DRILMAX® tubes / Precision tubes for drill rods

General information

Drilmax^® tubes for drill rods for exploration and directional drilling (e.g. HDD) are seamless cold-drawn precision steel tubes in accordance with EN 10305-1 and ASTM A519. They impress with their unique combination of excellent straightness and minimal residual stresses with perfectly balanced mechanical properties.

Drilmax^® tubes can be supplied in various strength classes with minimum yield strengths from 550 MPa up to 950 MPa. Their well-balanced mechanical properties allow only for minimum plastic deformation during the drilling process.

A wide range of dimensions, a possible variable wall thickness (TDT^®) as well as versatile further processing options such as thread cutting or quench-and-temper heat treatment make our Drilmax^® tube an ideal drill rod.

Dimensions

Outer diameter	25 mm - 168 mm	0.984'' - 6.614"
Inner diameter	20 mm - 155 mm	0.787'' - 6.102"
Lengths	Standard length 3 m Any length from 1.5 m to 6 m available	Standard length 9.843 ft Any length from 4.921 ft to 19.685 ft available
Other dimensions on request

Tolerances

Straightness tolerances

Standard straightness is 1 mm per 2 m.

Optimal straightnesses of 1 mm per 6 m can be supplied on request.

Tolerances on diameter

Outer Diameter	Tolerances
25.4 mm < OD ≤ 40 mm 1" < OD ≤ 1.575“	+0.13 mm / -0 mm +0.0051'' / -0"
40 mm < OD ≤ 80 mm 1.575“ < OD ≤ 3.150“	+0.25 mm / -0 mm +0.010'' / -0"
80 mm < OD ≤ 140 mm 3.150“ < OD ≤ 5.512“	+0.38 mm / -0 mm +0.015'' / -0"
140 mm < OD ≤ 168 mm 5.512“ < OD ≤ 7.008“	+0.45 mm / -0 mm +0.018'' / -0"

Inner Diameter	Tolerances
ID ≤ 75 mm ID ≤ 2.953"	+0 mm / -0.25 mm +0'' / -0,010"
75 mm < ID ≤ 140 mm 2.953“ < ID ≤ 5.512“	+0 mm/ -0.38 mm +0'' / -0.015"
ID > 140 mm ID > 5.512"	+0 mm / -0.45 mm +0'' / -0.018"

Steel grades and properties

Drilmax^® steel tubes are supplied in various steel grades with different mechanical properties. Other than the below listen steel grades can be supplied on request.

Due to their particularly high strength and hardness, Drilmax^® 850 and Drilmax^® 950 materials do not require a quench-and-temper treatment.

Chemical composition (% max.)

	C	Si	Mn	P	S	Cr	Mo
Drilmax^® 550	0.200	0.500	1.600	0.025	0.025
Drilmax^® 650	0.330	0.350	0.600	0.035	0.035	1.100	0.250
Drilmax^® 730	0.440	0.300	1.650	0.035	0.035
Drilmax^® 850	0.420	0.450	1.700	0.035	0.035	0.200	0.020
Drilmax^® 950	0.350	0.700	2.500	0.025	0.005	1.000	0.300

Mechanical Properties

	Yield Strength	Tensile Strength	Elongation	Delivery Condition
	R_p0.2(MPa) min	R_m (MPa) min	A_2" min (%)
Drilmax^® 550	550	690	18	+SR
Drilmax^® 650	650	790	15	+SR
Drilmax^® 730	730	820	15	+SR
Drilmax^® 850*	850	950	15	+SR
Drilmax^® 950*	950	1000	12	+N +SR
*Drilmax^® 850 and Drilmax^® 950 materials do not require a quench-and-temper treatment.

Drilmax^®tubes only reveal very low residual stresses (measured in transverse direction) of maximum 100 MPa for B, N und H dimensions. Ultra low residual stresses could be proposed upon request.

Quench-and-temper treatment (+QT)

A heat treatment process ("quenching and tempering") achieves higher mechanical properties and thus improves the wear resistance of the product.

Quenching and tempering is a combined heat treatment to optimize the mechanical properties of materials. This allows the highest strengths and hardnesses to be set with consistently good machining and forming properties.

Taylor Drawn Tubes (TDT®)

Drilmax^® tubes can also be supplied with variable wall thicknesses (TDT^® - Taylor Drawn Tubes). These allow a weight reduction of up to 30% compared to standard tubes.

Testing

In order to prove compliance with the high requirements for drill rods, we subject Drilmax^® tubes to extensive tests, for example:

Chemical analyses
Dedicated straightness checking
Mechanical testing
100% Eddy current testing e.g. ASTM E309, EN ISO 10893-1

Specific testing upon request, for example:

Continuous OD checking
Residual stress measurement
100% Ultrasonic testing e.g. ASTM E309, EN ISO 10893-10
Microstructural inspection
Further tests possible after consultation

Packaging

Drilmax^® tubes are packed and protected for shipment all over the world according to customer requirements.

The tubes are typically oiled inside and outside for temporary corrosion protection and delivered in bundles.

For more details about the packaging click here.