Sanbar® 20 is a high strength chromium-molybdenum steel with high fatigue strength and excellent wear resistance in the as-rolled condition.

Applications

Sanbar® 20 is used for integral drill steels, pilot rods and tapered rods.

Mechanical properties

Typical values, as-delivered condition
Proof strength Rp0.2
MPa (ksi)
Tensile strength Rm
Mpa (ksi)
Hardness
850 (123) 1300 (189) 37-43 HRC

Decarburization

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.

Machinability

Machining may require prior annealing.

Forging

Induction heating to 1000–1100°C (1830– 2010°F), 10–20 seconds. Cooling in air. Forging range 1100–850°C (2010–1560°F).
Fabrication

Heat treatment

Annealing (induction heating) 850–900°C (1560–1650°F). Cooling in air.
Fabrication

Normalizing (induction heating)

950–1050°C (1740- 1920°F). Cooling in air. Hardening of shank end (through hardening).
Fabrication

Hardening

Induction heating to 1000–1100°C (1830- 2010°F). Forced cooling in air or oil.

Tempering

Recommended hardness 50 HRC, temperature appr. 500°C (930°F)/0.5 hours. Tempering within one hour after hardening.

Sizes and tolerances

Fabrication