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