Felt is a textile that is produced by matting, condensing and pressing fibers together. Felt can be made of natural fibers such as wool or synthetic fibers such as polypropylene or polyester. There are many different types of felts for industrial, technical, designer and craft applications. While some types of felt are very soft, some are tough enough to form construction materials. Felt can vary in terms of fiber content, color, size, thickness,density and more factors depending on the use of the felt.
Felt gaskets can be used for: seals, washers, spacers, stripping, discs, anti-vibration and anti-squeak pads, bumpers, bushings, noise reduction linings, vibration mounts, shock dampeners, heat barriers, wipers, oil and grease retainers, dust and fuel oil filters, sound deadening, padding, insulation, plugs, light seals, lamp bases, lubrication wicking, dust shields and filters
Wool felts are manufactured to the SAE specification (Federal Specification C-F-206G).
- Wool felts are naturally flame resistant. Although they will burn when exposed to an open flame, when the flame is removed the felt will extinguish itself
- Wool felts remain unchanged in physical properties as it wears
- Wool felts can be hard enough to turn on a lathe and also soft enough to be sewn
- Wool felts do not ravel or fray
- Wool felts are highly absorbent and uninjured by continued oil/lubricant saturation
- Wool felts have significant resiliency
- Wool felts are an excellent insulator against cold, heat, sound and vibration.
Wool felts have been used in the gasketing industry for years; however a shift has been seen to Polyester felts for most applications.
Wool Felt Specifications
U.S. Federal Specifications C-F-206G Also Referenced as J314/ASTM D 461/ASTM D 2475/ASTM D 1777
|Type I Roll Felt SAE No.||F-1||F-2||F-3||F-5||F-7||F-10||F-11||F-13||F-15N||F-26N||F-50||F-51||F-55|
|Wool Content %||95||90||85||95||80||95||87||75||55||45||95||92||75|
|Chlorothene Solubles %||2.5||2.5||2.5||2.5||4.0||2.5||3.0||4.0||4.0||8.0||2.5||2.5||4.0|
|Water Solubles %||2.5||2.5||3.0||2.5||4.0||2.5||2.5||4.0||5.0||6.0||2.5||2.5||4.0|
|Total Solubles %||3.0||4.0||4.5||3.0||7.0||3.0||4.5||8.0||9.0||14.0||3.0||4.5||8.0|
|Ash Content %||1.5||2.0||2.5||2.0||3.0||2.5||3.0||3.5||4.0||5.0||1.5||2.5||3.0|
|Tensile Strength psi||500||500||400||400||250||225||200||75||75||75||500||300||200|
|Slit Resistance psi||33||28||22||18||12||8||6||2||2||2||33||22||12|
|Width = Inches||60||60||60 or 72||60||72||72||72||72||72||72||60||60 or 72||72|
|Color||White||Pink||Gray||White||Gray||White||Gray||Gray||Gray||Gray||White||Gray||Gray or Black|
|Thickness vs Biasis Weight
Thickness Range (inches)
|Thickness Range||Weight lb/yd||Thickness Range||Weight lb/yd||Thickness Range||Weight lb/yd|
|1/16||0.050 -0.075||0.10 -1.05|
|1/8||0.113 -0.137||1.90 -2.10||0.113 -0.137||1.80 -2.10||0.111 -0.139||1.45 -1.61|
|3/16||0.175 -0.201||2.85 -3.15||0.175 -0.201||2.78 -3.08||0.172 -0.204||2.17 -2.41|
|1/4||0.236 -0.264||3.80 -4.20||0.236 -0.264||3.61 -4.19||0.232 -0.268||2.90 -3.22|
|5/16||0.298 -0.328||4.75 -5.25||0.298 -0.328||4.50 -5.24||0.293 -0.333||3.62 -4.02|
|3/8||0.359 -0.391||5.70 -6.30||0.359 -0.391||5.41 -6.29||0.353 -0.397||4.35 -4.83|
|1/2||0.481 -0.519||7.60 -8.40||0.481 -0.519||7.21 -8.39||0.474 -0.526||5.80 -6.80|
|5/8||0.603 -0.647||9.50 -10.50||0.603 -0.647||9.01 -10.49||0.595 -0.655||7.25 -8.05|
|3/4||0.725 -0.775||11.40 -12.60||0.725 -0.775||10.81 -12.59||0.716 -0.784||8.70 -9.66|
|1||0.969 -1.031||15.20 -16.80||0.969 -1.031||14.41 -16.79||0.958 -1.042||11.60 -12.88|
|Thickness vs Biasis Weight
Thickness Range (inches)
|F-10/11/13 & 15N||F-26N||Thickness vs basis weight
Thickness Range (inches)
|F-50/51 & F-55 Grey & Black|
|Thickness Range||Weight lb/yd||Thickness + Weight||Thickness Range||Weight lb/yd|
|1/16||0.050 -0.075||Range "||Wgt lb/yd||3/64||0.040 -0.054||0.712 -0.788|
|1/8||0.105 -0.145||0.98 -1.14||.085-.165||0.90||1/16 **||0.056 -0.070||0.937 -1.013|
|3/16||0.165 -0.211||1.47 -1.71||5/64||0.071 -0.085||1.162 -1.238|
|1/4||0.224 -0.276||1.96 -2.28||.194-.306||1.80||3/32 **||0.087 -0.101||1.387 -1.463|
|5/16||0.284 -0.342||2.45 -2.85||Properties that apply to all Wool Felt Type I|
|3/8||0.343 -0.407||2.94 -3.42||.303-.447||2.70||Acid Resistance||Good (Except F-7)|
|1/2||0.462 -0.538||3.92 -4.56||.412-.588||3.60||Alkali Resistance (dilute)||Fair|
|5/8||0.581 -0.669||4.90 -5.70||Solvent Resistance||Excellent|
|3/4||0.700 -0.800||5.88 -6.84||.630-.870||5.40||Compression Recovery||99%|
|1||0.938 -1.062||7.84 -9.12||.848-1.152||7.20||Effect of Sunlight and Oxidation||None|
|Wool Felts are naturally flame resistant. Although they will burn when exposed to an open flame, when the flame is removed the felt will extinguish itself||Temperature Range||-80 to +200 F|
S.A.E. F-2 and F-3 are high-grade felts of slightly less density and durability than SAE F-1. These grades are recommended for vibration mountings and the same general purposes as F-1 but where a felt of slightly lower quality is adequate.
S.A.E. F-5, F-6 and F-7 are high-to-medium grade felts recommended for precision uses where resiliency and durability are important factors. SAE F-7 can be used in applications similar to those for F-5, but where slightly less durable material is permissible. These felts are commonly used for grease retainers, spacer strip seals, weather stripping, dust shields, and noise reduction linings.
S.A.E. F-10 and F-11 are high-grade, medium-to-low density felts, similar in quality to F-5, but recommended for uses where abrasion and wear are not important factors. These felts are often used for grease and oil retention (where the felt is confined and compressed in assembly), dust shields operating under less severe conditions, as well as for plug filters for gas and air.
S.A.E. F-13 and F-15 are low density felts with a wide range of uses where resistance to abrasion, durability, and wear are not important factors. Typical uses include: sound deadening; chassis strips; spacers; dust shields; pedal pads; dash liners; fuel oil filters; anti-rattle applications; grease and oil retention.
S.A.E. F-26 is suitable for packing and padding when held in place between other materials. This grade should not be used for mechanical purposes.
S.A.E. F-50 is a high-grade, high-density felt similar to SAE F-1, but produced in thicknesses below 1/8". This felt is recommended for mechanical applications where an accurate, thin, smooth, high-grade felt is required. Typical uses include ball and roller bearing oil-retaining washers and small, dust-excluding washers.
S.A.E. F-51 is a high-grade, high-density felt similar to F-3, but produced in thicknesses below 1/8". It is recommended for the same general uses as F-50, but in installations where tolerances and length of life are not as important. It is typically found in thin cut parts such as gaskets and liners.
S.A.E. F-55 is a medium-to-low density felt similar to SAE F-7, but made in thicknesses below 1/8". This felt is recommended for uses where high durability is not required, such as anti-squeak strips and sound deadening when glued or cemented to fiber board or metal panels.
Polyester has a wide range of industrial and electrical applications including gaskets, air filters, impregnated substrates, seals, wicks, moisture pads, and liquid filtration.
Benefits of Polyester Felt:
- Less expensive to wool felts
- Superior in dry heat applications
- Good resistance to most mineral and organic acids
- Excellent resistance to mildew and aging
- Variety of thicknesses and densities available
- Good resistance to abrasion
- Excellent for dirt collection
- Higher heat tolerance 300F and above
- Excellent resistance to bleaches and other oxidizing agents
- Good resistance to wearing and sunlight
- Available in wide range of colors for decorative use