O-6 Graph-Mo®  Annealed

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PACIFIC O6 has the highest machinability rating of any standard grade of tool steel. Free graphite in the microstructure gives unique machining characteristics; it also allows lubricant retention which gives non-seizing properties. O6 can usually be substituted for O1 in any application where machinability is a prime consideration.

Chemical Composition

Heat Analysis - ranges and limits %

C

1.45

Mn

.80

Si

1.00

Mo

0.25

Forging:

Heat to 1800/1950°F, do not forge below 1500°F.

Annealing:

Heat to 1410/1450°F and hold 1 to 4 hours depending on part size, cool at a maximum rate of 20°F per hour to 1000°F (cooling rate below 1000°F is not critical). Typical annealed hardness is 183/217 HB.

Stress Relieving:

Heat to 1200/1250°F for 1 hour minimum at temperature and cool in air.

Hardening:

Preheat complex and/or large tools to 1200°F. Heat slowly to austenitize at 1410/1450°F for 10 to 30 minutes. Quench in oil to an expected hardness of 63/65 HRC.

Temperting (Drawing):

Temper at 350/600°F for an hour at temperature to approximate hardness of 63 to 58 HRC.

Tempering Temperature °F

Approximate Hardness, HRC

300

61/63

400

60/62

500

58/60

600

56/59

700

52/54

800

48/54

900

45/49

1000

38/42

1100

32/38

1200

22/30

Shapes and Conditions Available
  • ​Annealed Rounds through 8" Diameter

  • SE® Flats & Squares from 1/2" through 3/4" Thickness