ACM - polyacrylate rubber

ACN - acrylonitrile; component in nitrile rubber

AEM - ethylene-acrylic rubber; copolymer of ethylene and methyl acrylate

AMS - Aerospace Material Specification

ANSI - American National Standards Institute

AQL - Acceptable Quality Level

ARP - Aerospace Recommended Practice

AS - Aerospace Standard

ASTM - American Society for Testing and Materials

AU - polyester-based polyurethane rubber

BR - polybutadiene rubber

CC - cubic centimeter

CO - homopolymer of epichlorohydrin

CR - polychloroprene rubber (Neoprene®)

CSM - chlorosulfonated polyethylene rubber (Hypalon®)

DIA - diameter

DIN - German standardization organization

ECO - copolymer of epichlorohydrin and ethylene oxide

EP, EPM, EPDM - ethylene-propylene rubber

EPA - Environmental Protection Agency

EU - polyether-based polyurethane rubber

FDA - Food and Drug Administration

FEP - tetrafluoroethylene

FEPM - tetrafluoroethylene-propylene rubber

FFKM - perfluoroelastomer

FKM - fluorocarbon elastomers

FMQ - fluoromethyl silicone rubber (fluorosilicone)

FPM - feet per minute; fpm = [shaft dia (in) x rpm x 3.1416] divided by 12

FSA - Fluid Sealing Association

FVMQ - fluoro vinyl methyl silicone rubber (fluorosilicone)

GRS - Government Rubber Styrene; now SBR

HNBR - hydrogenated nitrile rubber

HSN - highly saturated nitrile; alternative name for HNBR

IIR - butyl rubber; copolymer of isobutylene and isoprene

IN - inch

IR - isoprene rubber

IRHD - International Rubber Hardness degrees

IRM - Industry Reference Material, as in IRM 903 oil

ISO - International Organization for Standardization

JIC - Joint Industrial Conference on Hydraulic Standards for Industrial Equipment

KN/M - kilonewton per meter; SI equivalent of pli; sometimes a unit of measure in ASTM D 2000 line call-outs

MAX - maximum

MEK - methyl ethyl ketone

MIL - Military (specification)

MIL STD - Military Standard

MIN - minimum

MPA - megapascal; SI equivalent of psi; sometimes a unit of measure in ASTM D 2000 line call-outs

MQ - methyl silicone rubber

MS - Military Standard

NAS - National Aerospace Standard

NASA - National Aeronautics and Space Administration

NBR - nitrile butadiene rubber (Buna N); copolymer of acrylonitrile and butadiene

NBS - National Bureau of Standards

NR - natural rubber; polyisoprene

NSF - National Sanitation Foundation

OSHA - Occupational Safety and Health Administration

PLI - pounds per linear inch

PMQ - phenyl methyl silicone rubber

PSI - pounds per square inch

PTFE - polytetrafluoroethylene

PVMQ - phenyl vinyl methyl silicone rubber

RMA - Rubber Manufacturers Association

RPM - revolutions per minute

SAE - Society of Automotive Engineers

SBR - styrene butadiene rubber (Buna S); copolymer of styrene and butadiene

SG - specific gravity

SI - denotes The International System of Units (the modern metric system); taken from the French, “Le Système International d’Unités”

SPEC - specification

Tc - critical temperature

TFE - tetrafluoroethylene; a fluoroplastic

Tg - glass transition

TIR - Total Indicator Reading

UL - Underwriters Laboratories

UV - ultraviolet light

VMQ - vinyl methyl silicone rubber

XNBR - carboxylated nitrile rubber

“This list includes the abbreviations you will encounter most often in the sealing industry. Familiarity with them will save time as you design O-ring seals.”