F-1 Density and Thickness
S.A.E. Specification Number F-1
A.S.T.M. Federal and Felt Association Type and Grade Number 16R1
Density Percent Specific Gravity 34.2
Actual (1) Wool Content (Min.) Percent 95
Carbon Tetrachloride Soluble (Max.) Percent 2.5
Water Soluble (Max.) Percent 2.5
Carbon Tetrachloride & Water Soluble (Max.) Percent 3.0
Ash (Max.) Percent 1.5
Tensile Strength (Min.) PSI 500
Splitting Resistance (Min.) Lbs. Per 2" Width 33
Trade Designation Back Check
Color White
Standard Width Inches 60
THICKNESS WEIGHT
Nominal (inch) Limits (inch) Nominal (lbs/sq. yd.) Limits (lbs/sq. yd.)
1/8 0.113 - 0.137 2.0  1.90 - 2.10 
3/16 0.175 - 0.201 3.0 2.85 - 3.15
1/4 0.236 - 0.264 4.0 3.80 - 4.20
5/16 0.298 - 0.328 5.0 4.75 - 5.25
3/8 0.359 - 0.391 6.0 5.70 - 6.30
1/2 0.481 - 0.519 8.0 7.60 - 8.40
5/8 0.603 - 0.647 10.0 9.50 - 10.50
3/4 0.725 - 0.775 12.0 11.40 - 12.60
7/8 0.847 - 0.903 14.0 13.30 - 14.70
1 0.969 - 1.031 16.0 15.20 - 16.80