*Tribology in Materials and Manufacturing - Wear, Friction and Lubrication*

```
Figure 1.
```
*RAD (Aubert & Duval) steel composition analysis.*

willing to trade off a little of 5160's toughness for better wear resistance. However, with the continued improvement of 52,100 heat treat, this steel is starting to show up in larger knives and is showing excellent toughness. A modified 52,100 under the SR-101 name is being used by Jerry Busse in his Swamp Rat knives. The German equivalent 1.3505 has been discontinued [1].

It is used in precision ball bearings and many industrial applications. The balls made of this kind of material feature an excellent surface finish, considerable hardness, and a high load-carrying capacity, as well as excellent wear and deformation resistance. Chrome steel balls (**Figure 2**) are through hardened in order to achieve the maximum mechanical strength [2].

**Diameters:** 0.025–250 mm.

**Precision grades:** ISO 3290 G3–5–10–16–20–28–40–100–200–AFBMA G500/G1000.

**Equivalent materials to international standards:** AFN 100C6–B.S. EN 31–JIS G4805–SUJ2–ASTM 100C6.

**Through hardness index:**

Up to 12.7 mm HRC 62/66.

From 12.70 to 50.80 mm HRC 60/66.

From 50.8 to 70 mm HRC 59/65.

From 70 to 120 mm HRC 57/63.

**Mechanical properties:**

Critical tensile strength: 228 kgf/mm<sup>2</sup> .

Compression strength: 207 kgf/mm2 .

Modulus or elasticity: 20,748 kgr/mm2 . .

Specific weight: 7830 kgf/mm2
