THYROPLAST

®

2311

Technical Data Sheet

Chemistry

Comparable Standard: AISI P-20

Typical

C

Mn

Cr

Mo

Analysis % 0.4 1.5 1.9 0.2

Description

• THYROPLAST

®

2311 is a pre-hardened plastic mold steel.

• Supplied hardness of 280—325 HB (28-34 HRC)

Characteristics

• Good texturing compared to THYROPLAST 2312

• Good polishability compared to THYROPLAST 2312

Applications

•

Injection molds

•

Compression molds

•

Blow molds

•

Mold bases

•

Die holders

Physical Properties

Coefficient of

Thermal

Expansion

70

0

F – 200

0

F

6.8 X 10

-6

/

0

F

70

0

F – 400

0

F

7.2 X 10

-6

/

0

F

70

0

F – 575

0

F

7.4 X 10

-6

/

0

F

Thermal

Conductivity

212

0

F

235 Btu/in/ft

2

/

hr/

0

F

400

0

F

233 Btu/in/ft

2

/

hr/

0

F

575

0

F

221 Btu/in/ft

2

/

hr/

0

F

Heat Treatment

Welding

Soft Annealing

Tempering (See tempering diagram below)

• Tempering hardness is approximate and based on two hours at

temperature

• Please contact your Schmolz & Bickenbach heat treat representa-

tive for more detailed in

formation.

Temperature

Cooling

Hardness

1310

o

F - 1365

o

F Furnace

235 HB

Max

Temperature

o

F

212

392

572

752

932

1112

Hardness

HRC

51

50

48

46

42

36

1292

28

Polishing

P-20 can yield an A-2 surface finish when proper polishing proce-
dures are followed. Caution must be taken to avoid over polishing
which can lead to orange peel effect and pitting. A Schmolz &
Bickenbach

representative should be consulted

for additional

information.

Density:

0.283 lbs/in

3

(room temperature)

Mechanical Properties

Hardness

HRC

51 50 48 46 42 36

28

Tensile

Strength

KSI

251 242 228 215 193 165

134

32

123

All statements regarding the properties or utilization of the materials or prod-
ucts mentioned are for the purposes of description only. Guarantees regarding
the existence of certain properties or a certain utilization are only valid if
agreed upon in writing.

General Note

• Preheat insert to 600

0

F to 700

0

F. Maintain temperature above

600

0

F during welding.

• Use TIG with D.C. positive polarity.

• Depending on the application, various welding rods can be used.

P20 filler which will match the hardness of the base metal after
welding and tempering is commonly used. Please contact our
heat treatment facility for recommendations.

• Slowly cool down to 100

0

F– 150

0

F , preferably under an insulat-

ing blanket, before post heat.

• Post heat at 1000

0

F

one hour per inch of weld depth plus one ad-

ditional hour—double temper if possible. Exceeding 1050

0

F

could result in the loss of hardness.

Tempering Diagram

30

34

42

38

46

50

54

58

62

66

70

212

392

572

752

932 1112

0

1292 1472

Har

dness in HRC

Temperature °F

USA 800.323.1233

CANADA 800.268.4977

HEAT TREATMENT 800.265.0862

www.schmolz-bickenbach.us

www.schmolz-bickenbach.ca