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O-1 Annealed

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PACIFIC O1 is a general purpose, relatively non-performing grade which hardens from low temperatures (smaller tools and dies can be heated with a torch). When greater stability in heat treatment and/or wear resistance is required, consider PACIFIC A2. If machinability is of prime importance, consider Graph-Mo® (06).

Chemical Composition

Heat Analysis - ranges and limits %

C

.90

Mn

1.00

Cr

.50

W

.50

Forging:

Heat to 1800/1950°F, do not forge below 1550°F.

Annealing:

Heat to 1400/1450°F and hold 1 to 4 hours depending on part size, cool at a maximum rate of 40°F per hour to 1000°F (cooling rate below 1000°F is not critical). Typical annealed hardness is 183/212 HB.

Stress Relieving:

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

Hardening:

Preheat at 1200°F. Austenitize at 1450/1500°F for 10 to 30 minutes. Quench in oil to an expected hardness of 63/65 HRC.

Temperting (Drawing):

Temper at 350/500°F for an hour at temperature to approximate hardness of 62 to 57 HRC. Usually, when greater toughness is required than can be obtained by tempering above 500°F, it is customary to use a shock resisting tool steel such as PACIFIC S7.

Tempering Temperature °F

Approximate Hardness, HRC

300

63/65

350

62/64

400

61/63

450

60/62

500

58/60

600

55/57

700

51/53

800

48/40

900

44/47

1000

40/44

Shapes and Conditions Available
  • ​Annealed Rounds through 12" Diameter

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

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