Designation: F 36 – 99

AMERICAN SOCIETY FOR TESTING AND MATERIALS

100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM

Standard Test Method for

Compressibility and Recovery of Gasket Materials1
This standard is issued under the fixed designation F 36; the number immediately following the designation indicates the year of original
adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript
epsilon (e) indicates an editorial change since the last revision or reapproval.

This standard has been approved for use by agencies of the Department of Defense.

1. Scope tested, with the cylinder end hardened and ground. Penetrator
1.1 This test method covers determination of the short-time diameters for various types of gasket materials are as shown in
compressibility and recovery at room temperature of sheet- Table 1, unless otherwise specified.
gasket materials, form-in-place gaskets, and in certain cases, 3.1.3 Dial—An indicating dial, or dials, graduated in 0.025
gaskets cut from sheets. It is not intended as a test for mm (0.001 in.) to show the thickness of the specimen during
compressibility under prolonged stress application, generally the test. Readings shall be estimated to the nearest 0.002 mm
referred to as “creep,” or for recovery following such pro- (0.0001 in.).
longed stress application, the inverse of which is generally 3.1.4 Preload—A preload which shall include the weight of
referred to as “compression set.” Also, it is not intended for the penetrator itself and added weights to give the value
tests at other than room temperature. A resiliency characteristic specified within 61 %. Preloads for various types of gasket
(the amount recovered expressed as a percentage of the materials are as shown in Table 1, unless otherwise specified.
compressed thickness) may also be calculated from the test 3.1.5 Loading Device— A device for applying a specified
data where desired. major load to the upper end of the penetrator, which may
1.2 The values stated in SI units are to be regarded as the consist of an arrangement of dead weights, a hydraulic cylin-
standard. The values given in parentheses are for information der, an air cylinder, or any other device capable of applying the
only. major load at a slow uniform rate and to an accuracy of 61 %.
1.3 This standard does not purport to address all of the The major load shall be in addition to the specified preload.
safety concerns, if any, associated with its use. It is the Major loads for various types of gasket materials are as shown
responsibility of the user of this standard to establish appro- in Table 1, unless otherwise specified.
priate safety and health practices and determine the applica- 4. Test Specimen
bility of regulatory limitations prior to use.
4.1 The test specimen in Procedures A through K, inclusive,
2. Referenced Documents as described in Table 1, shall have a minimum area of 6.5 cm
2
2.1 ASTM Standards: 2 (1 in. ) in the form of a square, except in the case of cork

E 691 Practice for Conducting an Interlaboratory Study to composition, and cork and cellular rubber materials, which
Determine the Precision of a Test Method2 shall have a test specimen in the form of a circle 6.5 cm2 in
F 104 Classification System for Nonmetallic Gasket Mate- area. The test specimen shall consist of a single ply or a number
rials3 of superimposed plies sufficient to give a minimum nominal
thickness of 1.6 mm (1⁄16 in.) for all materials except cork
3. Apparatus composition, cork and rubber materials, and cork and cellular
3.1 The testing machine4 shall consist of the following rubber materials, for which the minimum nominal thickness
components: shall be 3.2 mm (1⁄8 in.). If applied to specimens outside of the
3.1.1 Anvil—A hardened and ground surface of 31.7 mm test thicknesses, the results shall be regarded merely as
(1.250 in.) minimum diameter. indicative. For specification purposes, agreement on compress-
3.1.2 Penetrator—A steel cylinder of diameter (within 6 ibility and recovery figures shall be reached between producer
0.025 mm (0.001 in.)) specified for the type of material being and consumer for those materials whose thickness in a single
ply or multiple plies does not fall within the tolerances of the
1
This test method is under the jurisdiction of ASTM Committee F-3 on Gaskets
two nominal thicknesses specified. The tolerances for the test
and is the direct responsibility of Subcommittee F03.20 on Mechanical Test thicknesses are listed in Classification F 104, Table 3. The
Methods. specimen shall contain no joint or separation within the
Current edition approved Apr. 10, 1999. Published May 1999. Originally minimum test area.
published as D 1147 – 51 T. Redesignated F 36 in 1963. Last previous edition
F 36 – 95(1997){1. 4.2 The test specimen for Procedure L, as described in Table
2
Annual Book of ASTM Standards, Vol 14.02. 1, shall be at least two in. long and wider than the penetrator
3

4
Annual Book of ASTM Standards, Vol 09.02. used for the test. It shall consist of a single ply and contain no
Contact ASTM for a list of recommended suppliers.

1
 F 36
TABLE 1 Conditioning and Test Loads for Gasket Materials
F 104 Identifica- Total Load (Sum of
Penetrator Major Major Load and
Proce- Type of Gasket tion First Two B Pre-Load
Conditioning Procedure Diameter, Load, N Pre-Load)
dureA Material Numerals of N (lbf)
mm (in.) (lbf)
Six-Digit Number N (lbf) MPa (psi)
A Compressed asbestos F 11, F12, 1 h at 100 6 2°C (2126 3.6°F). Cool in 6.4 22.2 1090 1112 34.5
sheet; asbestos F 51, F52 desiccator over a suitable desiccant at (0.252) (5) (245) (250) (5000)
beater sheet; flexible 21 to 30°C (70 to 85°F)
graphite

H Asbestos paper and millboard F 13 4 h at 100 6 2°C (2126 3.6°F). Cool as 6.4 4.4 218 222 6.89
in Procedure A (0.252) (1) (49) (50) (1000)

F Cork composition F 21, F23 at least 46 h at 21 to 30°C (70 to 85°F) 28.7 4.4 440 445 0.69
Cork and cellular rubber and 50 to 55 % relative humidity (1.129) (1) (99) (100) (100)

B Cork and rubber F 22 at least 46 h at 21 to 30°C (70 to 85°F) 12.8 4.4 351 356 2.76
and 50 to 55 % relative humidity (0.504) (1) (79) (80) (400)

G Treated and untreated papers F 31, F32, 4 h at 21 to 30°C (70 to 85°F) over a 6.4 4.4 218 222 6.89
from cellulose or other F 33, F34 suitable desiccant followed immediately (0.252) (1) (49) (50) (1000)
organic fibers by at least 20 h at 21 to 30°C and 50
to 55 % relative humidity

J Compressed nonasbestos F 71, F72 1 h at 100 6 2°C (212 6 3.6°F). Cool in 6.4 22.2 1090 1112 34.5
sheet; non-asbestos beater desiccator over a suitable desiccant at (0.252) (5) (245) (250) (5000)
sheet 21 to 30°C (70 to 85°F)

K Non-asbestos paper and F 73 4 h at 100 6 2°C (212 6 3.6°F). Cool as 6.4 4.4 218 222 6.89
millboard in Procedure J. (0.252) (1) (49) (50) (1000)
L Fluorocarbon polymer F 42 None 6.4 22.2 534 556 17.25
(Form-in-Place Gaskets) (0.252) (5) (120) (125) (2500)
A
Procedures C, D, and E were deleted from Test Method F 36 to ensure compliance with conditioning procedures in Sections 6 and 7 of Specification D 1170, which
appear as part of Classification F 104.
B
Anhydrous calcium chloride and silica gel have been determined to be suitable desiccants.

joint or separation. No thickness tolerances are given for preloaded thickness of the specimen. Immediately apply the
gaskets covered by this procedure. Test results shall be major load in a slow uniform manner so that the total load is
regarded merely as indicative. attained within 10 s. Guide the penetrator in its descent so that
the surface remains parallel to the surface of the anvil.
5. Conditioning of Specimens Maintain the total load for a period of 60 s, and record the
5.1 Specimens shall be conditioned as specified for the thickness of the specimen. Immediately remove the major load,
particular type of material. Conditioning procedures for vari- and after a period of 60 s record the thickness of the specimen
ous types of gasket materials are as shown in Table 1, unless under the original preload. This is the recovered thickness.
otherwise specified.
5.2 If a mechanical means of maintaining 50 to 55 % 8. Number of Tests
relative humidity is not available, a tray containing a saturated
8.1 A minimum of three tests shall be run on separate
solution of reagent grade magnesium nitrate (Mg(NO3)2·6H
specimens taken from the same sample and the results aver-
2O) shall be placed in the chamber to provide the required
aged.
relative humidity. In all cases where testing is conducted
outside the area of specified humidity, specimens shall be
9. Calculation
removed from the chamber one at a time as needed.
9.1 The compressibility and recovery shall be calculated as
6. Temperature of Test follows:
6.1 The test shall be conducted with both specimen and Compressibility, % 5 @~P 2 M!/P# 3 100 (1)
apparatus at a temperature of 21 to 30°C (70 to 85°F).
Recovery, % 5 @~R 2 M!/~P 2 M!# 3 100 (2)
7. Procedure
where:
7.1 Determine the amount of deflection of the penetrator at P 5 thickness under preload, mm (in.),
each of the loads used in the test with no specimens present. M 5 thickness under total load, mm (in.), and
Add the absolute value of this penetrator deflection to the R 5 recovered thickness, mm (in.).
thickness under total load M in 9.1 to obtain a corrected 9.2 When desired, the resiliency shall be calculated as
reading. The values are machine constants which may vary for follows:
different instrument designs.
Resiliency, % 5 @~R 2 M!/M# 3 100 (3)
7.2 Center the test specimen upon the anvil and apply the
preload and maintain for a period of 15 s, and record the 9.2.1 The aforementioned values are illustrated in Fig. 1.

2
 F 36

FIG. 1 Representation of Specimen Thickness

11.2 In Column 3 are the coefficients of variation for the

10. Report physical properties listed in Column 2. In Column 4 are the
10.1 Report the following information: maximum differences (ranges) that should be considered ac-
10.1.1 Identification and classification number of material ceptable for two results that are considered to be from
tested, nominally identical specimens. These are expressed as a
10.1.2 Nominal thickness of material tested, percent of the mean value. The precision data are based on tests
10.1.3 Letter designation of test procedure, conducted on Type 1, Type 2, and Type 3 gasket material
10.1.4 Number of tests performed, specimens. Eleven laboratories participated in the round robin
10.1.5 Temperature of specimens and apparatus, and on Type 1 and Type 3 gasket material. Nine laboratories
10.1.6 Compressibility and recovery results for each speci- participated in the round robin on the Type 2 gasket material.
men tested and average for the sample. There was one operator at each of the laboratories testing five
specimens.
11. Precision and Bias 5
NOTE 1—The critical differences were calculated using t 5 1.960
11.1 This precision and bias statement was developed using which is based on infinite degrees of freedom.
Practice E 691. (See Table 2.) NOTE 2—m 5 3 was used in the calculations of the repeatability and
reproducibility values because this specification requires a minimum of
three tests to be run.
12. Keywords
5
Supporting data are available from ASTM Headquarters. Request RR: F03-
1005.
12.1 compressibility; gasket; material; recovery; resiliency

TABLE 2 Interlaboratory Test Program

Coefficient of Variation (percent Acceptable Range of Two ResultsA
Physical Property of mean) (S %) max (percent of mean) (D2S %) max
Type 1 Type 2 Type 3 Type 1 Type 2 Type 3
Repeatability % Compressibility 3.7 2.3 2.2 6.0 3.6 3.6
(single operator) % Recovery 4.6 1.1 2.6 7.3 1.8 4.2

Reproducibility % Compressibility 6.6 7.8 7.9 19.2 21.9 22.1

(Multilaboratory) % Recovery 7.2 0.9 10.7 21.2 3.0 30.0
A
A result is an average of three determinations.

The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection
with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such
patent rights, and the risk of infringement of such rights, are entirely their own responsibility.

This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and
if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards
and should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your
views known to the ASTM Committee on Standards, 100 Barr Harbor Drive, West Conshohocken, PA 19428.