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MOLDABLE EXOTHERMIC PAD MATERIALS
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STEEL FOUNDERS SOCIETY OF AMERICA
Tentative Specification for
MOLDABLE EXOTHERMIC PAD MATERIALS
SFSA Designation: 3 OT-6 5
Issued:
1965
This Tentative Specification has been approved by the Societys Specifications Committee and reviewed by
the material producers. The Tentative Specification shall be in effect for two (2) years and, if not revised
in that time, it shall be advanced to Standard. Suggestions for revisions should be addressed to the Steel
Founders Society at 606 Terminal Tower, Cleveland, Ohio
44113.
Scope
1.1
This specification covers all exothermic mate-
rials which are molded to shape and rammed in place
against the pattern to extend the feeding range in
steel castings.
Acknowledgment
2.1 When specified, a vendor shall indicate this
specification number in all quotations and when
acknowledging purchase orders.
Identification
3.1 Containers for exothermic moldable materials
shall be plainly marked Exothermic Moldable Mate-
rial or by vendors trade name.
3.2 The name of the manufacturer and batch num-
ber shall be legibly marked on each container.
Quality
4.1 The material shall be of uniform color and free
from foreign materials.
Sample Preparation
5.1 The number of containers to be sampled by the
consumer for routine testing shall depend on the
number of containers in a shipment.
5.1.1 When the shipment consists of 10 containers
or less, the number of containers sampled at random
shall be not less than 2 and preferably 4.
5.1.2 When the shipment consists of more than 10
containers, the number of containers to be sampled
at random shall be not less than 4 containers and
preferably 30 percent of the total number in the ship-
ment or a maximum of 10 containers (see Note 1).
5.2 The composite sample shall not weigh less than
40 pounds or greater than 200 pounds and shall be
obtained by taking approximately equal weights from
each random selected container in the sample lot.
5.2.1 The composite sample shall be reduced by
quartering until a minimum 20-pound sample is
o b t a i n e d .
5.2.2 An alternate method for reducing the gross
sample is by the use of a sample splitter, such as
6.
Technical Requirements
described in the AFS Foundry Sand Handbook, Sev-
enth Edition, Section III.
5.3 Identification of the sample shall indicate mate-
rial, trade name, manufacturer, batch number, source
of shipment and date shipment was received.
5.4 In case of a dispute between manufacturer and
purchaser, the number of units to be sampled shall
be according to ASTM C322, Procedure C.
N
OTE
I.-Fractional units shall be converted to the nearest whole
number, e.g.,
4.4 containers=4 containers, 4.6 containers= 5
containers.
6.1 Contaminators in the Exothermic Pad Material.
61.1 Boron

. less than 0.005 percent
6.1.2 Lead

. less than 0.050 percent
6.1.3 Magnesium . less than 0.100 percent
6.1.4 Tin

less than 0.120 percent
6.1.5 Zinc

less than 0.150 percent
6.2 Exothermic Pad Requirements for Casting Sound
Plate.
6.2.1 By the use of a tapered exothermic pad of pre-
scribed dimension, a 1x5x15-inch carbon steel plate,
cast horizontally, shall conform to Class 1 of ASTM
E-7 l-52 in respect to internal soundness.
6.3 Bend Test.
6.3.1 The degree of bend in a normalized carbon
steel plate (0.25 percent 0.03 percent carbon) shall
be equal to or greater than 70 degrees. The bend
portion of the bar shall not contain more than 3
cracks, none of which shall be over inch long in
any direction. Figure 1 illustrates how measurement
of degrees (bend) is taken (see Note 2
)
6.3.2 In the event the degree of bend is less than
70 degrees, a machined bend bar from a standard keel
block poured in the same heat and similarly heat
treated shall be bend tested and meet 120 degrees
bend.
6.3.2.1 Failure of the machined bend bar to meet the
120-degree requirement permits the retesting for de-
gree of bend with a test plate cast in another heat.
N
OTE
2 .-If the fractured surface of the bend bar indicates a
visual flaw in the steel, such as sand and/or slag inclusions,
porosity and/or gas holes, etc., a retest shall be permitted. 6.4 Contaminators in the Steel Casting.
6.4.1 The maximum pickup (see Note 3 ) in alumi-
num, boron and silicon 0.025 inch below the test
casting-exothermic pad interface shall conform to the
following limitations:
6.4.1.1 Aluminum
0.10
percent
6.4.1.2 Silicon . . . . . . . . . . . . 0.80 percent
6.4.1.3 Boron
none
N
OTE
3 .-Pickup refers to the percentage of contaminators in
excess of the base composition of the test plate.
Figure l-Sketch illustrating measurement of angle of bend.
7.
Acceptance Tests
7.1 Contaminators in Exothermic Pad Materials.
7.1.1 The manufacturer, upon request, shall furnish
within ten days to the purchaser a certified representa-
tive analysis of the contaminators as indicated in 6.1.
7.2 Test Procedure for Determining Feeding Ability
of Exothermic Pad Material.
7.2.1 Cast horizontally a steel plate with pad as
shown in Figure
2.
7.2.1.1 Foundry practice for test shall be according
to drawing shown in Figure
2.
7.2.1.2 Test plate shall be cast in 0.22-0.28 percent
carbon steel,
7.2.1.3 Pouring temperature of the steel shall be not
less than 2850 degrees F.

l
NO

ON
PAD
7
Figure
of test plate with exothermic pad giving dimensions
of plate, exothermic pad, and riser. Gate location indicated.
7.2.2 Pressure blast plate, remove gate and riser, and
then normalize 1600 degrees F.
7.2.3 Place film adjacent to plate-pad interface, radio-
graph test plate to a quality level of a 2-2T (ASTM-
EY4) for internal shrinkage (see Note 4).
N
O T E
4.-Further checking of the exothermic material not re-
wired if test plate does not conform to Class 1 of ASTM E-71-52
in respect to Internal soundness.
7.3 Performing the Bend Test.
7.3.1 Preparation of bend specimen.
7.3.1.1 Remove bend bar specimen from plate as
illustrated in Figure 3. It shall be machined (see
7.3.1.2 ) to 1 by inch in section with corners
rounded to a radius not over
inch.
7.3.1.2 No machining or grinding will be permitted
on casting-plate interface of the bend specimen.
Figure 3-Sketch showing location of bend bar specimen and location
of specimen for spectrographic analyses.
7.3.2 Test procedure.
7.3.2.1 The bend test specimen shall stand being
bent cold through an angle of 70 degrees.
7.3.2.2 The bend shall be made around a pin 1 inch
in diameter with the unmachined pad-casting inter-
face being on the outside of the bend (the side of
the bend specimen experiencing tensile forces).
7.3.2.3 The bend test shall be conducted in accord-
ance with ASTM A-370, Methods and Definitions.
7.4 Determining Pickup of Contaminators (Al, Si
and B) in Test Plate.
7.4.1 Analytical procedures shall be limited to spec-
trographic methods.
7.4.2 Specimen for spectrographic analysis shall be
taken approximately 9 inches from the riser end of
the plate and 1 inch from either edge of the plate.
7.4.3 Spectrographic tests shall be made 0.025 inch
below the plate-exothermic pad interface. 8.
7.4.4 Preparation of casting surface for spectro-
graphic analysis shall be by machining (see Note 5
)
7.4.5 Spectrographic test for base composition (Al,
Si and B) shall be made from the side opposite the
exothermic pad. Use the spectrographic specimen from
Item 7.4.2.
7.4.6 Referee Procedure.
7.4.6.1 Surface preparation for spectrographic analy-
sis for contaminators shall be by either electropolishing
or by a milling operation.
Note 5
.-Surface preparation for spectrographic analysis by
grinding is permitted provided the ground surface is cleaned with
l-l
hydrochloric acid to remove any aluminum or silicon con-
taminators. Grinding is permitted without hydrochloric acid
cleaning provided a silicon carbide belt is used for aluminum
sparking and an aluminum oxide belt is used for silicon sparking.
Number of Tests
8.1 One test plate shall be made for each shipment
under test.
9.
10.
8.2
One bend test shall be made for each shipment
under test.
8.3 If any bend specimen shows defective machin-
ing or develops a visual flaw, it may be discarded and
another specimen substituted.
Retest
9.1
If the result of the bend test does not conform
to the requirements specified, another test plate may
be cast.
Rejection
10.1 Any rejection based on tests made in accordance
with Section 7 which does not conform to the re-
quirements in Section 6 shall be reported to the manu-
facturer within two weeks by the purchaser.
10.2 Materials which do not conform to the require-
ments of this specification will be subject to rejection
by the purchaser.