Rock drill steel

Drill steel developed for the manufacturing of top-hammer rock drill rods, available in various steel grades.

Sandvik drill steel is characterized by a number of properties that enable efficient production:

  • High fatigue strength and toughness
  • High resistance to wear and permanent distortion
  • Close tolerances (for automated manufacturing process)
  • Uniform response to heat treatment
  • Uniform straightness (eliminating the need for straightening)

Sandvik's rock drill steel can be supplied as hollow or solid, hot-rolled, round or hexagon bar.

List of materials
GradeDescriptionApplications
Sanbar 20 A high-strength chromium-molybdenum steel with high fatigue strength and excellent wear resistance in the as-rolled condition. Integral drill steels, pilot rods and tapered rods
Sanbar 23 An air-hardening, high chromium-molybdenum alloy steel with good response to surface induction hardening and suitable for carburizing. It has high fatigue strength and wear resistance in the case-hardened condition. Extension rods, shank rods and tapered rods
Sanbar 61 A high-strength silicon steel with good toughness and impact resistance in the as-rolled condition. Tapered rods, pilot rods and integral drill steels
Sanbar 64 An air-hardening, high nickel alloy steel with good response to carburizing. It has excellent fatigue strength and wear resistance in the case hardened condition. Extension rods, shank rods and tapered rods
Decarburization
GradeDecarburization
Sanbar 20 The maximum permissible decarburization depth is 0.20 mm (0.008 in.) on the outer surface and 0.10 mm (0.004 in.) on the inner surface.
Sanbar 23 The maximum permissible decarburization depth is 0.30 mm (0.012 in.) on the outer surface and 0.20 mm (0.008 in.) on the inner surface.
Sanbar 61 The maximum permissible decarburization depth is 0.30 mm (0.012 in.) on the outer surface and 0.10 mm (0.004 in.) on the inner surface.
Sanbar 64 The maximum permissible decarburization depth is 0.30 mm (0.012 in.) on the outer surface and 0.20 mm (0.008 in.) on the inner surface.
Mechanical properties (typical values*)
GradeProof strength Rp0.2
MPa (ksi)
Tensile strength Rm
Mpa (ksi)
Hardness
Sanbar 20 850 (123) 1300 (189) 37-43 HRC
Sanbar 23 1000 (145) 1350 (196) 38-44 HRC
Sanbar 61 820 (119) 1350 (196) 38-44 HRC
Sanbar 64 900 (131) 1250 (181) 37-44 HRC

*As-delivered condition

Chemical composition (nominal, %)
GradeCSiMnP MaxS MaxCrNiMo
Sanbar 20 0.97 0.2 0.3 0.025 0.020 1.0 - 0.2
Sanbar 23 0.24 0.3 0.5 0.020 0.025 3.1 - 0.5
Sanbar 61 0.41 1.5 0.9 0.025 0.020 0.7 0.5 0.2
Sanbar 64 0.22 0.3 0.7 0.020 0.025 1.3 2.9 0.2