ASTM D2475-22

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:D2475 −22
Standard Specification for
Felt
This standard is issued under the fixed designation D2475; 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 (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 This specification covers all standard types of felt in the
form of rolls and sheets that are suitable for mechanical use. D123 Terminology Relating to Textiles
D461 Test Methods for Felt (Withdrawn 2003)
Certain special-purpose felts are also covered.
D4845 Terminology Relating to Wool
1.2 This specification is not applicable to felt-like products
2.2 Federal Standard:
that utilize weaving, knitting, stitching, or bonding such as
C-F-206, Felt Sheet: Cloth Felt, Wool, Pressed
papermaker’s felt.
2.3 Felt Manufacturers Council:
1.3 Tradepracticeinthefeltindustrydealsinpounds,yards,
FS14-68/71 Wool Felt Standard Specifications
and inches, therefore the values stated in inch-pound units are
2.4 SAE Standard:
to be regarded as standard. The values in SI units are provided
J314b Felts-Wool and Part Wool
as information only.
3. Terminology
1.3.1 The specification referenced in 2.2 uses only inch-
pound units.
3.1 Definitions:
3.1.1 felt, n—a textile structure characterized by interlock-
1.4 This international standard was developed in accor-
ing and consolidation of its constituent fibers.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Development of International Standards, Guides and Recom-
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
mendations issued by the World Trade Organization Technical
Standards volume information, refer to the standard’s Document Summary page on
Barriers to Trade (TBT) Committee.
the ASTM website.
The last approved version of this historical standard is referenced on
www.astm.org.
AvailablefromStandardizationDocumentsOrderDesk,Bldg.4SectionD,700
This specification is under the jurisdiction of ASTM Committee D13 on Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
Textiles and is the direct responsibility of Subcommittee D13.13 on Wool and Felt. Available from the Northern TextileAssociation, 230 Congress Street, Boston,
CurrenteditionapprovedJune1,2022.PublishedJuly2022.Originallyapproved MA 02110.
in 1965. Last previous edition approved in 2013 as D2475 – 01(2013) which was Available from the Society of Automotive Engineers, 2 Pennsylvania Plaza,
withdrawn in January 2022 and reinstated in June 2022. DOI: 10.1520/D2475-22. New York, NY 10001.
TABLE 1 Wool Sheet Felt: Thickness and Mass (Weight)
2 2
Thickness, in. Thickness, mm Mass (Weight) lb/yd Mass (Weight) kg/m
ASTM (NTA)
Color Tolerances Tolerances
Class
Nominal Nominal Nominal Tolerances Nominal Tolerances
Sheets Cut Parts Sheets Cut Parts
26S1 White 0.125 ± 0.014 ± 0.016 3.17 ± 0.35 ± 0.41 1.50 ± 0.10 0.81 ± 0.05
26S4 Gray 0.188 0.016 0.018 4.78 0.41 0.46 2.25 0.15 1.22 0.08
0.250 0.020 0.022 6.35 0.51 0.56 3.00 0.20 1.63 0.11
0.313 0.022 0.024 7.95 0.56 0.61 3.75 0.25 2.04 0.14
0.375 0.024 0.026 9.52 0.61 0.66 4.50 0.30 2.44 0.16
0.500 0.030 0.032 12.70 0.76 0.81 6.00 0.40 3.26 0.22
0.625 0.035 0.037 15.88 0.89 0.94 7.50 0.45 4.07 0.24
0.750 0.040 0.042 19.05 1.02 1.07 9.00 0.50 4.89 0.27
0.875 0.046 0.048 22.23 1.17 1.22 10.50 0.55 5.70 0.30
1.000 0.051 0.053 25.40 1.30 1.35 12.00 0.60 6.52 0.33
1.250 0.062 0.065 31.75 1.57 1.65 15.00 0.70 8.15 0.38
1.500 0.072 0.075 38.10 1.83 1.91 18.00 0.80 9.77 0.43
1.750 0.083 0.085 44.45 2.11 2.16 21.00 0.90 11.40 0.49
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2475−22
TABLE1 Continued
2 2
Thickness, in. Thickness, mm Mass (Weight) lb/yd Mass (Weight) kg/m
ASTM (NTA)
Color Tolerances Tolerances
Class
Nominal Nominal Nominal Tolerances Nominal Tolerances
Sheets Cut Parts Sheets Cut Parts
2.000 0.094 0.098 50.80 2.39 2.49 24.00 1.00 13.03 0.54
2.500 0.115 0.119 63.50 2.92 3.02 30.00 1.05 16.29 0.57
3.000 0.136 0.141 76.20 3.45 3.58 36.00 1.10 19.55 0.60
34S1 White 0.125 0.012 0.014 3.17 0.30 0.36 2.00 0.10 1.09 0.05
34S2 White 0.188 0.012 0.014 4.78 0.30 0.36 3.00 0.15 1.63 0.08
34S3 White 0.250 0.016 0.018 6.35 0.41 0.46 4.00 0.30 2.17 0.16
34S4 Gray 0.313 0.017 0.019 7.95 0.43 0.48 5.00 0.35 2.71 0.19
0.375 0.019 0.021 9.52 0.48 0.53 6.00 0.40 3.26 0.22
0.500 0.022 0.024 12.70 0.56 0.61 8.00 0.50 4.34 0.27
0.625 0.026 0.028 15.88 0.66 0.71 10.00 0.60 5.43 0.33
0.750 0.029 0.031 19.05 0.74 0.79 12.00 0.70 6.52 0.38
0.875 0.032 0.034 22.23 0.87 0.86 14.00 0.75 7.60 0.41
1.000 0.036 0.038 25.40 0.91 0.97 16.00 0.80 8.69 0.43
1.250 0.042 0.045 31.25 1.07 1.14 20.00 0.90 10.86 0.49
1.500 0.049 0.052 38.10 1.24 1.32 24.00 1.00 13.03 0.54
1.750 0.056 0.059 44.45 1.42 1.50 28.00 1.10 15.20 0.60
2.000 0.063 0.067 50.80 1.60 1.70 32.00 1.20 17.38 0.65
2.500 0.076 0.080 63.50 1.93 2.03 40.00 1.25 21.72 0.68
3.000 0.090 0.095 76.20 2.29 2.41 48.00 1.30 26.06 0.71
43S1 White 0.125 0.012 0.014 3.17 0.30 0.36 2.50 0.30 1.36 0.16
43S2 White 0.188 0.012 0.014 4.78 0.30 0.36 3.75 0.35 2.04 0.19
43S3 White 0.250 0.014 0.016 6.35 0.36 0.41 5.00 0.40 2.71 0.22
43S4 Gray 0.375 0.016 0.019 9.52 0.41 0.48 7.50 0.50 4.07 0.27
0.500 0.019 0.022 12.70 0.48 0.56 10.00 0.60 5.43 0.33
0.625 0.022 0.025 15.88 0.56 0.64 12.50 0.70 6.79 0.38
0.750 0.025 0.028 19.05 0.63 0.71 15.00 0.80 8.15 0.43
0.875 0.027 0.030 22.23 0.69 0.76 17.50 0.90 9.50 0.49
1.000 0.030 0.033 25.40 0.76 0.84 20.00 1.00 10.86 0.54
1.250 0.036 0.040 31.15 0.91 1.02 25.00 1.10 13.56 0.60
1.500 0.041 0.045 38.10 1.04 1.14 30.00 1.20 16.29 0.65
1.750 0.047 0.051 44.45 1.19 1.30 35.00 1.30 19.00 0.71
2.000 0.053 0.058 50.80 1.35 1.47 40.00 1.40 21.72 0.76
2.500 0.064 0.070 63.50 1.63 1.78 50.00 1.45 27.15 0.79
3.000 0.075 0.082 76.20 1.90 2.08 60.00 1.50 32.58 0.81
56S1 White 0.125 0.010 0.014 3.17 0.25 0.36 3.25 0.40 1.76 0.22
56S2 White 0.188 0.010 0.014 4.78 0.25 0.36 4.90 0.50 2.66 0.27
56S3 White 0.250 0.011 0.016 6.35 0.28 0.41 6.50 0.60 3.53 0.33
S654 Gray 0.375 0.013 0.018 9.52 0.33 0.46 9.75 0.80 5.29 0.43
0.500 0.016 0.022 12.70 0.41 0.56 13.00 1.00 7.06 0.54
0.625 0.018 0.024 15.88 0.46 0.61 16.25 1.10 8.82 0.60
0.750 0.020 0.026 19.05 0.51 0.66 19.50 1.20 10.59 0.65
0.875 0.022 0.028 22.23 0.56 0.71 22.75 1.30 12.35 0.70
1.000 0.025 0.031 25.40 0.63 0.79 26.00 1.40 14.12 0.76
1.250 0.029 0.036 31.75 0.74 0.91 32.50 1.50 17.65 0.81
1.500 0.033 0.040 38.10 0.84 1.02 39.00 1.60 21.18 0.87
1.750 0.038 0.046 44.45 0.97 1.17 45.50 1.70 24.71 0.92
2.000 0.042 0.051 50.80 1.07 1.30 52.00 1.80 28.24 0.98
2.500 0.050 0.061 63.50 1.27 1.55 65.00 1.85 35.29 1.00
3.000 0.058 0.070 76.20 1.47 1.78 78.00 1.90 42.35 1.03
68S1 White 0.125 0.007 0.013 3.17 0.18 0.33 4.00 0.50 2.17 0.27
68S2 White 0.188 0.007 0.014 4.78 0.18 0.36 6.00 0.75 3.26 0.41
68S3 White 0.250 0.007 0.015 6.35 0.18 0.38 8.00 1.00 4.34 0.54
68S4 Gray 0.375 0.009 0.018 9.52 0.23 0.46 12.00 1.10 6.52 0.60
0.500 0.011 0.020 12.70 0.28 0.51 16.00 1.20 8.69 0.65
0.625 0.013 0.022 15.88 0.33 0.56 20.00 1.30 10.86 0.71
0.750 0.015 0.024 19.05 0.38 0.61 24.00 1.40 13.03 0.76
0.875 0.017 0.026 22.23 0.43 0.66 28.00 1.50 15.20 0.81
1.000 ±0.019 ±0.028 25.40 ±0.48 ±0.71 32.00 ±1.60 17.38 ±0.87
1.250 0.022 0.032 31.75 0.56 0.81 40.00 1.70 21.72 0.92
1.500 0.026 0.036 38.10 0.66 0.91 48.00 1.80 26.06 0.98
1.750 0.029 0.041 44.45 0.74 1.04 56.00 1.90 30.41 1.03
2.000 0.032 0.046 50.80 0.81 1.17 64.00 2.00 34.75 1.09
2.500 0.038 0.055 63.50 0.97 1.40 80.00 2.05 43.44 1.11
D2475−22
3.1.2 machined felt, n—a felt structure achieved by the 3.1.6 relative density, n—the ratio of the mass of a volume
interaction of a suitable combination of mechanical energy, of felt to the mass of an equivalent volume of water,
chemical action, moisture and heat causing the constituent
alternatively, use density.
fibers to migrate and interlock.
3.1.3 needled felt, n—astructurecomposedentirelyoffibers 4. Types of Felts
physically interlocked and reoriented through the action of
4.1 ASTM Classification:
felting needles.
4.1.1 The ASTM Classification number in Tables 1-3 is the
3.1.4 For standard terminology relating to wool, refer to
percent specific gravity of that class. It may be computed from
Terminology D4845.
the mass (weight), thickness, and area values in these tables.
3.1.5 For definitions of other textile terms used in these test
This number is followed by the letter R or S, which designates
methods, refer to Terminology D123.
the method of manufacture as roll or sheet form, respectively.
3.1.5.1 Discussion—For the purpose of this document, there
The last digit is the overall quality index in decreasing order of
are only two types of felt, machined and needled. All other
quality from one to four (see Note 1).
terms alluded to as types of felt, such as papermakers, black,
4.1.2 To obtain the average density of the different felts in
unsupported, supported, part wool, wool, etc. are considered to
be simply terms describing attributes of these two types of lb/ft , multiply the percent specific gravity number of the first
felts. column of Tables 1-4 by 0.6243.
TABLE 2 Roll and Sheet Felt Corresponding Classifications—Properties and General Description
Corresponding
Physical Requirements General Description
Classifications
ASTM
Min. Tensile Min. Split Resis-
(NTA) Normal Width Thickness: Available Range
Fed.
Strength, tance
Classifi-
SAE Spec.
A Color
N/50
cation
J314b C-F-
lbf/2 in.
psi kPa mm in. cm in. mm
width
width
14R1 . . . . . . white 72 183 0.125–0.500 3.17–12.7
17R1 . . . . . . white 72 183 0.125–1.000 3.17–25.4
17R2 F26 8R5 . . . . gray 72 183 0.125–1.000 3.17–25.4
18R1 F10 9R1 225 1551 8 35 white 72 183 0.063–1.000 1.60–25.4
18R2 F11 9R2 200 1379 6 26 gray 72 183 0.063–1.000 1.60–25.4
18R3 F12 9R3 100 690 3 13 gray 72 183 0.063–1.000 1.60–25.4
18R4 F13 9R4 75 517 2 9 gray 72 183 0.063–1.000 1.60–25.4
18R5 F15 9R5 75 517 2 9 gray 72 183 0.063–1.000 1.60–25.4
26R1 F5 12R1 400 2758 18 79 white 60 152 0.063–1.000 1.60–25.4
26R2 F6 12R2 275 1896 16 71 gray 60 or 72 152 or 183 0.063–1.000 1.60–25.4
26R3 F7 12R3 250 1724 12 53 gray 72 183 0.063–1.000 1.60–25.4
26R3X F55 12R3X 200 1379 . . gray 60 or 72 152 or 183 0.063–0.094 1.60–2.39
34R1 F1 16R1 500 3448 33 147 white 60 152 0.125–1.000 3.17–25.4
34R1X F50 16R1X 500 3448 . . white 60 152 0.047–0.092 1.19–2.39
34R2 F2 16R2 500 3448 28 124 not blk or gray 60 152 0.047–1.000 1.19–25.4
34R3 F3 16R3 400 2758 22 97 gray 60 152 0.125–1.000 3.17–25.4
34R3X F51 16R3X 300 2069 . . gray 60 or 72 152 or 183 0.047–0.094 1.19–2.39
38R1 . 18R1 600 4137 35 154 white 60 152 0.125–0.500 3.17–12.7
38R2 . . 550 3792 30 132 gray 60 152 0.125–0.500 3.17–12.7
26S1 . 12S1 400 2758 18 79 white 36 91 0.125–3.000 3.17–76.2
26S4 . . 300 2069 16 71 gray 36 91 0.125–3.000 3.17–76.2
34S1 . 16S1 500 3448 32 141 white 36 91 0.125–3.000 3.17–76.2
34S2 . 16S3 400 2758 28 124 white 36 91 0.125–3.000 3.17–76.2
34S3 . 16S4 300 2069 20 89 white 36 91 0.125–3.000 3.17–76.2
34S4 . . 400 2758 22 97 gray 36 91 0.125–3.000 3.17–76.2
43S1 . 20S1 500 3448 44 196 white 36 91 0.125–3.000 3.17–76.2
43S2 . 20S3 400 2758 40 178 white 36 91 0.125–3.000 3.17–76.2
43S3 . 20S4 300 2069 32 142 white 36 91 0.125–3.000 3.17–76.2
43S4 . . 400 2758 36 160 gray 36 91 0.125–3.000 3.17–76.2
56S1 . 26S1 600 4137 48 212 white 36 91 0.125–3.000 3.17–76.2
56S2 . 26S3 500 3448 46 205 white 36 91 0.125–3.000 3.17–76.2
56S3 . 26S4 400 2758 36 160 white 36 91 0.125–3.000 3.17–76.2
56S4 . . 400 2758 40 178 gray 36 91 0.125–3.000 3.17–76.2
68S1 . 32S1 600 4137 50 222 white 36 91 0.125–2.500 3.17–63.5
68S2 . 32S3 500 3448 48 212 natural 36 91 0.125–3.000 3.17–76.2
68S3 . 32S4 400 2758 40 178 natural 36 91 0.125–3.000 3.17–76.2
68S4 . . 400 2758 46 205 gray 36 91 0.125–2.500 3.17–63.5
A
NTA refers to Northern Textile Association.
D2475−22
TABLE 3 Roll Felt Thicknesses and Weights
NOTE 1—The F-50, F-51, and F-55 classifications are available in limited thickness ranges. See Table 2.
ASTM
Thickness Tolerances Mass (Weight) Per Unit Area
(NTA) SAE Fed. Spec. Trade Designa-
Color Inches Millimetres Nominal Tolerances
Classifi- J314b C-F-206 tion
Nominal Nominal
2 2
Roll Cutparts Roll Cutparts lb/yd kg/m
cation
14R1 . . White Soft Pad 0.125 ± 0.040 ± 0.048 3.18 ± 1.02 ± 1.22 0.83 ± 0.10 0.45 ± 0.05
0.250 0.056 0.064 6.35 1.42 1.63 1.65 0.20 0.90 0.11
0.375 0.072 0.082 9.53 1.83 2.08 2.48 0.30 1.35 0.16
0.500 0.088 0.098 12.70 2.24 2.49 3.30 0.40 1.79 0.22
17R1 . . White Soft Pad 0.125 0.040 0.044 3.18 1.02 1.12 0.9 0.09 0.49 0.05
17R2 F-26 8R5 Gray 0.250 0.056 0.062 6.35 1.42 1.58 1.8 0.18 0.98 0.10
0.375 0.072 0.079 9.53 1.83 2.01 2.7 0.27 1.47 0.15
0.500 0.088 0.098 12.70 2.24 2.49 3.6 0.36 1.95 0.20
0.750 0.120 0.135 19.05 3.05 3.43 5.4 0.54 2.93 0.29
1.000 0.152 0.170 25.40 3.86 4.32 7.2 0.72 3.91 0.39
18R1 F-10 9R1 White Firm Pad 0.125 0.020 0.023 3.18 0.51 0.58 1.06 0.08 0.58 0.04
18R2 F-11 9R2 Gray Firm Pad 0.188 0.023 0.026 4.78 0.58 0.66 1.59 0.12 0.86 0.07
18R3 F-12 9R3 Gray Firm Pad 0.250 0.026 0.031 6.35 0.66 0.79 2.12 0.16 1.15 0.09
18R4 F-13 9R4 Gray Firm Pad 0.313 0.029 0.033 7.95 0.74 0.84 2.65 0.20 1.44 0.11
18R5 F-15 9R5 Gray Firm Pad 0.375 0.032 0.036 9.53 0.81 0.91 3.18 0.24 1.73 0.13
0.500 0.038 0.044 12.70 0.97 1.12 4.24 0.32 2.31 0.18
0.625 0.044 0.050 15.88 1.12 1.27 5.30 0.40 2.89 0.22
0.750 0.050 0.060 19.05 1.27 1.52 6.36 0.48 3.46 0.26
0.875 0.056 0.065 22.23 1.42 1.65 7.42 0.56 4.03 0.30
1.000 0.062 0.070 25.40 1.58 1.78 8.48 0.64 4.62 0.35
26R1 F-5 12R1 White Ex Firm Pad 0.063 0.007 0.012 1.60 0.18 0.31 0.75 0.04 0.41 0.02
26R2 F-6 12R2 Gray Ex Firm Pad 0.094 0.007 0.012 2.39 0.18 0.31 1.12 0.05 0.61 0.03
26R3 F-7 12R3 Gray Ex Firm Pad & 0.125 0.014 0.016 3.18 0.36 0.41 1.53 0.08 0.83 0.04
Gray or Black 0.188 0.016 0.018 4.78 0.41 0.46 2.29 0.12 1.24 0.07
26R3X F-55 12R3X . Lining 0.250 0.018 0.020 6.35 0.46 0.51 3.06 0.16 1.66 0.09
0.313 0.020 0.022 7.95 0.51 0.56 3.82 0.20 2.07 0.11
0.375 0.022 0.025 9.53 0.56 0.64 4.59 0.24 2.49 0.13
0.500 0.026 0.029 12.70 0.66 0.74 6.12 0.32 3.32 0.18
0.625 0.030 0.033 15.88 0.76 0.84 7.65 0.40 4.15 0.22
0.750 0.034 0.038 19.05 0.86 0.97 9.18 0.48 4.98 0.26
0.875 0.038 0.042 22.23 0.97 1.07 10.71 0.56 5.82 0.30
1.000 0.042 0.046 25.40 1.07 1.17 12.24 0.64 6.65 0.35
34R1 F-1 16R1 White Backcheck & 0.047 0.007 0.010 1.19 0.18 0.25 0.75 0.04 0.41 0.02
34R1X F-50 16R1X White Ball Bearing 0.063 0.007 0.010 1.60 0.18 0.25 0.98 0.04 0.53 0.02
34R2 F-2 16R2 Not Black Backcheck 0.078 0.007 0.010 1.98 0.18 0.25 1.20 0.04 0.65 0.02
or Gray 0.094 0.007 0.011 2.39 0.18 0.28 1.43 0.04 0.78 0.02
34R3 F-3 16R3 Gray Backcheck & 0.125 0.012 0.015 3.18 0.31 0.38 2.00 0.10 1.09 0.05
34R3X F-51 16R3X Gray Ball Bearing 0.188 0.013 0.017 4.7
...