Skip to main content

FR-4

FR-4 (or FR4) is a NEMA grade designation for glass-reinforced epoxy laminate material. FR-4 is a composite material composed of woven fiberglass cloth with an epoxy resin binder that is flame resistant (self-extinguishing).

"FR" stands for "flame retardant", and does not denote that the material complies with the standard UL94V-0 unless testing is performed to UL 94, Vertical Flame testing in Section 8 at a compliant lab. The designation FR-4 was created by NEMA in 1968.

FR-4 glass epoxy is a popular and versatile high-pressure thermoset plastic laminate grade with good strength to weight ratios. With near zero water absorption, FR-4 is most commonly used as an electrical insulator possessing considerable mechanical strength. The material is known to retain its high mechanical values and electrical insulating qualities in both dry and humid conditions. These attributes, along with good fabrication characteristics, lend utility to this grade for a wide variety of electrical and mechanical applications.

Grade designations for glass epoxy laminates are: G-10, G-11, FR-4, FR-5 and FR-6. Of these, FR-4 is the grade most widely in use today. G-10, the predecessor to FR-4, lacks FR-4's self-extinguishing flammability characteristics. Hence, FR-4 has sincewhen? replaced G-10 in most applications.
Fenhar FR-4 epoxy resin systems typically employ bromine, a halogen, to facilitate flame-resistant properties in FR-4 glass epoxy laminates. Some applications where thermal destruction of the material is a desirable traitcitation needed will still use G-10 non flame resistant.
by fenharxz.com August 7, 2024
mugGet the FR-4 mug.

The FR4WG

The act of eating shit out of a dudes ass while fondling one dudes balls while beating the other dude off into a glass cup and the drinking the shit down his own throat with the cum.
its close to the sleepy white boy The FR4WG
by Zombie ranark July 3, 2010
mugGet the The FR4WG mug.
When pp go ouchie :,,,(
Oh no mah weewee

I‘M GONNA gzhtb .7uüuzih6d fxcv<>‡ÙÅ∂‚fr4gt65!
by DerHeisseWikiEditor January 8, 2025
mugGet the gzhtb .7uüuzih6d fxcv<>‡ÙÅ∂‚fr4gt65 mug.

Share this definition

Sign in to vote

We'll email you a link to sign in instantly.

Or

Check your email

We sent a link to

Open your email