NEMA FR-1 is a high-pressure laminate with a cotton linter or alpha cellulose paper and a phenolic resin formulation with a flame-retardant additive contributing to its UL-94 V-1 U.L. flammability rating. A plasticizer is also added to the formula to permit good punching at elevated temperatures. Bleached and unbleached saturation kraft paper can also be used depending on the material thickness and application.

FR-1 has similar properties to NEMA grade XP and is not recommended for tubes or molded rods. It has fair moisture absorption properties, a 130°C electrical/mechanical continuous use temperature index but poor resistance to organic solvents and oils.

Punched FR-1 parts are most often specified for electrical insulation in switches, motors and other applications but should not be used with radio frequency applications.

FR-1 complies with the specifications for Mil-I-24768/24 and IEC 60893 PF CP 205

NEMA FR-2 has a similar paper and flame-retardant resin formulation as FR-1 with an additional plasticizer that permits good punching from ambient to slightly elevated temperatures. It may also be referred to as an FR grade cold punching paper phenolic.

FR-2 has similar properties to NEMA grade XPC and is not recommended for tubes or molded rods. It has fair moisture absorption properties, a 75°C electrical/mechanical continuous use temperature index for thicknesses <.062” but="" a="" 105°c="" electrical="" mechanical="" continuous="" use="" temperature="" index="" for="" thicknesses="">.062”. Chemical resistance to organic solvents and oils is poor because plasticizers may be leached from the laminate. </.062”>

Punched FR-2 parts are most often specified for electrical insulation in switches, motors, and other applications where flame retardant material is needed. Good dielectric loss properties enable its’ use in radio frequency applications.

FR-2 complies with the specifications for Mil-I-24768/25 and IEC 60893 PF CP 308

NEMA FR-3 is a high-pressure laminate with a cotton linter or alpha cellulose paper and an epoxy resin formulation with a flame-retardant additive contributing to its UL-94 V-1 U.L. flammability rating. Bleached kraft paper can also be used depending on the material thickness and application. A plasticizer is added to the resin formula to permit clean punching from ambient to slightly elevated temperatures. It is not recommended for tubes or molded rods.

It has good moisture resistance and relatively low dielectric losses under conditions of adverse humidity and temperature. It has better moisture and chemical resistance than FR-1 and FR-2, a 90°C electrical/mechanical continuous use temperature index for thicknesses <.062” but="" a="" 110°c="" electrical="" mechanical="" continuous="" use="" temperature="" index="" for="" thicknesses="">.062”.</.062”>

FR-3 complies with the specifications for Mil-I-24768/26 and IEC 60893 EP CP 201

Punched FR-3 parts are most often specified for electrical insulation in switches, motors, and other applications where flame retardant material is needed. Good dielectric loss properties enable its’ use in radio frequency applications.

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