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EngiRef

Engineering formulas, materials, constants, unit conversions, reference tables, and study tools.

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6Disciplines
17Categories
119Formula Library
56Materials
134Units
28Constants
Formula libraryUnit converterMaterials databaseReference tablesConstantsCustom formulasQuizFavorites

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EngiRef workspaces

Deep-linkable routes expose the engineering workflows that make sense on web.

FormulasBrowse engineering formulas by discipline and category.Unit ConverterConvert engineering units with local browser tools.MaterialsSearch materials and compare engineering properties.Reference TablesReview bolt, pipe schedule, and wire gauge tables.Custom FormulasCreate and calculate browser-local custom formulas.Calculation HistoryReview saved browser-local calculations and quiz attempts.QuizPractice engineering formula flashcards.FavoritesReview saved reference records.

6 items

Disciplines

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Mechanical

Statics, dynamics, machine design, and mechanics

Electrical

Circuits, power, electromagnetics, and electronics

Civil

Structures, beams, columns, and hydraulics

Thermo

Heat transfer, cycles, and energy systems

Fluids

Fluid mechanics, pipe flow, and hydraulics

Materials

Stress, strain, material properties, and failure

17 items

Categories

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Statics

Included in Categories.

Dynamics

Included in Categories.

Machine Design

Included in Categories.

DC Circuits

Included in Categories.

AC Circuits

Included in Categories.

Beams

Included in Categories.

Columns

Included in Categories.

Hydraulics

Included in Categories.

119 items

Formula Library

Reference equations and calculators

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Normal Stress

Stress is force per unit area acting on a material

Statics

Normal Strain

Strain is the ratio of deformation to original length

Statics

Hooke's Law

Linear relationship between stress and strain in elastic region

Statics

Shear Stress

Average shear stress from transverse force

Statics

Torque

Torque (moment) from a perpendicular force

Statics

Moment of Inertia (Rectangle)

Second moment of area for a rectangular cross-section about centroidal axis

Statics

Moment of Inertia (Circle)

Second moment of area for a circular cross-section

Statics

Newton's Second Law

Force equals mass times acceleration

Dynamics

56 items

Materials

Engineering reference tables

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AISI 1018 Carbon Steel

carbon-steel

carbon-steel

AISI 1020 Carbon Steel

carbon-steel

carbon-steel

AISI 1045 Carbon Steel

carbon-steel

carbon-steel

AISI 4130 Chromoly Steel

carbon-steel

carbon-steel

AISI 4140 Alloy Steel

carbon-steel

carbon-steel

AISI 4340 Alloy Steel

carbon-steel

carbon-steel

ASTM A36 Structural Steel

carbon-steel

carbon-steel

ASTM A992 Structural Steel

carbon-steel

carbon-steel

134 items

Units

Conversion and unit definitions

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Meter

length

lengthm

Kilometer

length

lengthkm

Centimeter

length

lengthcm

Millimeter

length

lengthmm

Micrometer

length

lengthµm

Nanometer

length

lengthnm

Inch

length

lengthin

Foot

length

lengthft

28 items

Constants

Scientific constants

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Speed of Light in Vacuum

Exact defined value in SI. Maximum speed in universe.

fundamentalc

Planck Constant

Exact defined value in SI. Relates photon energy to frequency.

fundamentalh

Reduced Planck Constant

h/(2π). Common in quantum mechanics.

fundamentalℏ

Elementary Charge

Exact defined value in SI. Charge of a proton.

fundamentale

Avogadro's Constant

Exact defined value in SI. Particles per mole.

fundamentalNᴀ

Gravitational Constant

Universal gravitation constant. F = GMm/r².

fundamentalG

Fine Structure Constant

Dimensionless. Characterizes electromagnetic interaction strength.

fundamentalα

Vacuum Permittivity

Electric constant. Appears in Coulomb's law.

electromagneticε₀

15 items

Metric Bolts

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Item 1

Included in Metric Bolts.

Item 2

Included in Metric Bolts.

Item 3

Included in Metric Bolts.

Item 4

Included in Metric Bolts.

Item 5

Included in Metric Bolts.

Item 6

Included in Metric Bolts.

Item 7

Included in Metric Bolts.

Item 8

Included in Metric Bolts.