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tolerance

TOL-er-uhnss /ˈtɒlərəns/

nounB2SATTOEFLIELTS

TechnicalIndustrialProfessional

The allowable amount of variation in a specified physical dimension or value before it is considered defective.

In engineering, tolerance is not about patience or social acceptance; it is the strict, mathematically calculated boundary of acceptable physical error.

The story behind the word. In the mid-20th century, engineers adopted the Latin word for 'endurance' to describe how much physical stress, heat, or dimensional deviation a machine part could 'endure' before failing completely.

Word relationships

allowance: Allowance is a planned difference between two mating parts, whereas tolerance is the permissible variation in a single part.
margin: Margin is a general term for safety or error, while tolerance is a specific, measured engineering limit.

intolerance: In physical systems, intolerance refers to a complete inability to withstand variation, leading to immediate failure.

Commonly confused with

clearance: Clearance is the physical space between two moving parts, while tolerance is the allowed variation in their individual sizes.

Word family

tolerate (verb): To allow or endure without adverse reaction.
tolerant (adjective): Showing tolerance or capability of enduring variation.

Collocations

tight tolerance
close tolerance
allowable tolerance
zero tolerance

Example sentences

"The engine pistons were machined to an incredibly tight tolerance of just five micrometers." Aerospace manufacturing manual

Memory hook

Think of a toll bridge that can tolerate cars up to a certain weight limit, but anything over will cause it to collapse. The endurance limit of a metal part.

When not to use

Do not use to describe a complete lack of rules or total chaos; it refers to a highly controlled, calculated margin.

Fun facts

The Hubble Space Telescope's primary mirror was famously polished to a tolerance of 1/50th the width of a human hair, yet a tiny error still required a space shuttle mission to correct.