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4 december

smack somone under 5’3 on the head with a book
‘hits head with a book’ me:what’s that for?
then:it’s 4 december
by foxibingoo December 3, 2020
mugGet the 4 decembermug.

4 fingers up

You like Ava
Cisco put 4 fingers up.(takes pic)
by El Chapo08 May 31, 2022
mugGet the 4 fingers upmug.

group 4

"have you seen that group 4? DAMN i wish i could join..."
by RitaSkeeter December 16, 2008
mugGet the group 4mug.

4$R

4eva Solid Records- A Music label created by Rappers: Ayee $lick, Honcho Mar, Key 23 and GSM Hugo
You heard that new song by Honcho? 4$R Definitely on their way yo!
by sheloverico_ July 11, 2022
mugGet the 4$Rmug.

4-0 Asian

4-0 Asian refers to the Asian people in the San Francisco Bay Area. More specifically, people in the 408 area code, such as those in San Jose. 4-0 Asians typically love getting boba and raving.
Person 1: Hey, what are you tryna do tonight?
Person 2: Shii i'ma hit this rave, prob hit in-n-out after, and get some boba.
Person 1: You HELLA 4-0 Asian bruh.
Person 2: BRUHHH
by SanAndreas123 September 14, 2025
mugGet the 4-0 Asianmug.

4 fingers up

samia was throwing her 4 fingers up, bet she be fuckin bitches and getting money
by rzzsamia December 3, 2022
mugGet the 4 fingers upmug.

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-4mug.

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