F-51 SAE Pressed Felt
F-51 SAE Pressed Felt is a durable thin-gauge pressed wool felt with a minimum of 92% wool content (SAE Number F-51, NTA Number 34R3, Commercial Standard Grade 16R3X), rated for service from -80°F to 200°F. It delivers 300 psi minimum tensile strength, 99% recovery within 1 minute after 10% deflection, and a Mullen bursting strength of 225 psi. Available in grey in thin precision thicknesses of 3/64″, 1/16″, 5/64″, and 3/32″, it is suited for gaskets, liners, bearing seals, and applications where precision tolerance, life, and quality are not as exacting.
Key Properties
- Tensile Strength (min): 300 psi — ASTM D412
- Mullen Bursting Strength (1/8″): 225 psi — ASTM D461
- Recovery Within 1 Minute After 10% Deflection: 99% — ASTM D461
- Specific Gravity: 0.34 — ASTM D461
- Temperature Range: -80°F to 200°F — —
Liquid Absorption: > 170% (1.0 sp gr) — ASTM D461
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- Specifications
- Applications
- General Info
- FAQs
Physical Properties
| Property | Value | Test Method |
| Material / Substrate | Pressed Felt | — |
| Color | Grey | — |
| Minimum Wool Content | 92% | — |
| SAE Number | F-51 | — |
| NTA Number | 34R3 | — |
| Commercial Standard Grade | 16R3X | — |
| Specific Gravity | 0.34 | ASTM D461 |
| Density | 15.60 lb/sq yd | ASTM D461 |
| Thickness | 3/64″, 1/16″, 5/64″, 3/32″ | — |
Mechanical Properties
| Property | Value | Test Method |
| TENILE STRENGTH (MINIMUM) | 300 psi | ASTM D412 |
| Elongation 100% (100 PSI) | 9 | ASTM D461 |
| Mullen Bursting Strength (1/8″) | 225 psi | ASTM D461 |
| Recovery Within 1 Minute After 10% Deflection | 99% | ASTM D461 |
Thermal Properties
| Property | Value | Test Method |
| Temperature Range | -80°F to 200°F | — |
| Thermal Condition @ 70°F | 0.32 btu/(h·ft²·°F) | ASTM D461 |
| Thermal Expansion | 0 | ASTM D461 |
Acoustic / Physical Properties
| Property | Value | Test Method |
| Noise Reduction Coefficient (NRC), 1 in | 0.55 | ASTM D461 |
| Coefficient of Friction | 0.37 | ASTM D461 |
| Air Perm (1/16″) | 15-40 cfm/sq ft/0.5″ H2O | ASTM D461 |
| Capillarity (Wicking Height, 575 SSU, 70°F) | 4 | ASTM D461 |
| Liquid Absorption | > 170% (1.0 sp gr) | ASTM D461 |
Chemical Resistance
| Property | Value | Test Method |
| Abrasion Resistance | Excellent | — |
| Acid Resistance, Concentrated | Fair – Good | ASTM D461 |
| Acid Resistance, Dilute | Excellent | ASTM D461 |
| Alkali Resistance, Concentrated | Low | ASTM D461 |
| Alkali Resistance, Dilute | Fair | ASTM D461 |
| Solvent Resistance | Excellent | — |
- Gaskets and liners for industrial assemblies where thin grey felt is required and performance demands are moderate
- Bearing seals and seal strips in applications where precision tolerance requirements are less exacting
- General-purpose industrial felt components in thin gauges where grey color is appropriate
- Wicks and filtration strips in low-demand applications requiring a grey, oil-resistant felt
- Cost-effective thin-gauge felt for applications where the F-50 specification exceeds requirements
Common industries: Industrial equipment, general manufacturing, gasket fabrication, light industrial, packaging.
F-51 SAE Pressed Felt is a grey thin-gauge pressed wool felt with a minimum of 92% wool content and a specific gravity of 0.34, designated SAE F-51 and Commercial Standard Grade 16R3X. It is intended for gaskets, liners, bearing seals, and applications where precision tolerance and performance requirements are less exacting than those met by the F-50 grade.
Available in thin gauges from 3/64″ to 3/32″, it is an economical grey alternative to the white F-50 in applications where white color or the highest tensile specification is not required. Its oil-resistant construction allows it to hold up under multiple uses.
The material provides a coefficient of friction of 0.37, noise reduction coefficient of 0.55 at 1 in, and thermal condition of 0.32 btu/(h·ft²·°F) at 70°F. Air permeability is 15–40 cfm/sq ft/0.5″ H2O. Density is 15.60 lb/sq yd. Data was obtained by ASTM D461 test methods, ASTM D2475 Standards, and NTA wool felt specifications.
What differentiates F-51 SAE Pressed Felt from the F-50 grade?
F-51 SAE Pressed Felt is the grey, lower-specification counterpart to the white F-50 grade. It has a lower minimum wool content (92% vs. 95%), lower minimum tensile strength (300 psi vs. 500 psi), slightly higher air permeability range (15–40 vs. 15–25 cfm/sq ft), and lower liquid absorption (>170% vs. >180%). The TDS explicitly states it is suited for applications where precision tolerance, life, and quality are not as exacting as those for F-50. Both grades share the same thin-gauge thickness range (3/64" to 3/32") and density profile.
Why is hardness important for felt selection in industrial applications?
Hardness in pressed felt governs dimensional stability under load, which matters in gaskets, liners, and bearing seals where the felt must maintain its section without excessive deflection. F-51's 99% recovery after deflection confirms its elastic response to load cycling, supporting reasonable performance in applications where the more demanding specifications of F-50 or F-1 are not required.
What is the temperature range for F-51 SAE Pressed Felt?
F-51 SAE Pressed Felt is rated for service from -80°F to 200°F, as listed on the TDS.
Is F-51 SAE Pressed Felt suitable for oil-contact and industrial environments?
Yes. The TDS identifies F-51 as an oil-resistant fabric with excellent abrasion, acid (dilute), and solvent resistance. It is explicitly positioned for applications where precision tolerance, life, and quality are not as exacting. No specific compliance standards are cited on the TDS; data was obtained by ASTM D461 test methods, ASTM D2475 Standards, and NTA wool felt specifications.
How should F-51 SAE Pressed Felt be specified?
Specify grade (F-51 SAE Pressed Felt), thickness, dimensional tolerances, and finished format.
