Spring Applications 231

active coils

The number of coils in a coil spring that move or deflect under a load. The number of active coils is necessary to know when ordering a compression spring.

angle

A shape formed by two lines sharing a common endpoint. An angle can also be formed by two lines that intersect.

angular return torque

The potential torque generated by a torsion spring's deflection and return to its free state. Angular return torque is a factor that affects torsion spring selection.

axis

An imaginary straight line that passes through the center of an object. A coil spring reacts to force applied to its axis.

beam spring

A simple type of spring made of a small, flat piece of metal often used in automotive applications, such as suspension systems. Beam springs are also called flat springs and leaf springs.

Belleville washer

A conical washer that can be stacked to create a powerful compression spring and is often used to support applications with high loads and insufficient space for a coil spring. Belleville washers may also be called cone-disc springs or cupped spring washers.

buckling

A type of permanent deformation that occurs when a compression spring bends outward rather than compressing along its axis. Buckling, which often results from improper loading or improper compression spring specifications, appears as a bowing or sideways deflection.

chassis

The metal frame of a motor vehicle. A chassis uses a multi-leaf spring to reduce vibration when driving.

chrome silicon

A type of metal made from chrome and silicon that is used in large-diameter spring wire. Chrome silicon can handle higher stresses than chrome vanadium.

chrome vanadium

A type of metal made from chrome and vanadium that is used in large-diameter spring wire. Chrome vanadium is an excellent choice for high-stress applications.

clamps

A device that holds objects together by applying inward pressure. Clamps often use torsion springs to absorb and exert torque.

clash allowance

The amount of space available between a spring's compression height under maximum load and its solid compression height. Clash allowance in compression springs is usually a 10% difference between maximum load height and solid compression to avoid coil clash.

closed and grounded ends

A compression spring end coil that is flattened and almost completely contacting the next coil. Closed and grounded ends, or squared and grounded ends, allow for better load transfer but are the most expensive type of end coil.

closed ends

A compression spring end coil that is cut to provide almost direct contact with the next coil. Closed ends, or squared ends, improve a compression spring's ability to handle load.

coil clash

An event that occurs when a compression spring is subjected to a shock load causing solid compression. Coil clash may be prevented by using a 10% clash allowance.

coil compression spring

A type of spring designed to compress and become smaller when presented with a compressive load. Coil compression springs are often referred to simply as compression springs, but there are other types of springs and spring-like objects used as compression springs in special applications.

coil spring

A type of spring formed by winding strips of metal around a cylinder or cone to create a helical or conical shape. Coil springs are the most common type of spring.

compression spring

A type of coil spring designed to compress and become smaller when presented with a compressive load. Compression springs usually refer to coil compression springs, but there are other types of compression springs used for special applications.

compressive load

A force or pressure that attempts to flatten or squeeze a material. Compressive loads are supported by compression springs.

cone-disc spring

A conical washer that can be stacked to create a powerful compression spring and is often used to support applications with high loads and insufficient space for a coil spring. Cone-disc springs may also be called Belleville washers or cupped spring washers.

conical spring

A type of coil spring that has a cone shape. Conical springs are sometimes used when there is insufficient space for a helical spring and in some dynamic load applications.

constant-force extension spring

A type of spring designed with curved strips of steel that prevent uncoiling except under constant force. Constant-force extension springs are commonly used in timers and movie cameras.

corrosion

The gradual chemical attack on a metal. Corrosion is sometimes caused by atmospheric exposure.

critical stress regions

An area of a component most likely to be permanently deformed or damaged when in use. Critical stress regions include the hooks of extension springs.

cupped spring washer

A conical washer that can be stacked to create a powerful compression spring and is often used to support applications with high loads and insufficient space for a coil spring. Cupped spring washers may also be called Belleville washers or cone-disc springs.

dampen

To lessen a force. Springs dampen forces in mechanical systems.

deflection

The degree of change in shape when a force is applied. Deflection occurs when springs change their shape to absorb forces.

deform

To change or distort an object's shape. Deformed metal has permanently lost its original shape.

double-direction torsion spring

A type of torsion spring that transmits torque in two directions. Double-direction torsion springs are designed with an unwound loop in the middle.

dynamic load

A type of load that changes in the direction or degree of force during operation. The presence of dynamic loads affects spring design and selection.

elastic

Capable of resuming original shape after experiencing temporary deformation. Elastic devices include the many different types of springs.

elastic limit

The point at which objects no longer resume their original shape after temporarily changing shape. Springs operating outside of their elastic limit may become permanently deformed.

end coil

The outermost coil in a coil spring that is used to attach the spring to the machine it supports. End coils can also be called end plates.

end plate

The outermost coil in a coil spring that is used to attach the spring to the machine it supports. End plates can also be called end coils.

extension spring

A type of spring designed to support tensile, or pulling, loads. Extension springs are also called tensile springs.

extension springs

A type of spring designed to support tensile, or pulling, loads. Extension springs are also called tensile springs.

failure

The complete loss of performance. Failure can be the result of gradual wear, incorrect operating variables, or insufficient lubrication.

fatigue

A condition in which metals begin to fail after being exposed to improper load conditions, too many deflections, or extreme temperatures. Fatigue can result in the failure of a mechanical device.

flat spring

A simple type of spring made of a small, flat piece of metal often used in automotive applications, such as suspension systems. Flat springs are also called beam springs and leaf springs.

fluid-based spring

A type of spring that uses pressurized liquids to provide resistance to force. Fluid-based springs are sometimes supported by mechanical springs.

force

A push or pull that gives energy to an object. Forces change an object's motion or state of rest.

free length

The length of a spring when not under load. Free length is one of the variables needed when ordering a spring.

friction

A force that resists motion between two objects that are in contact with each other. Friction is a type of contact force used in mechanical systems.

gas-charged spring

A type of spring that uses pressurized or compressed gas to provide resistance to force. Gas-charged springs are sometimes supported by mechanical springs.

grounded ends

A compression spring end coil that is flattened to provide an improved contact surface. Grounded ends help to improve a compression spring's ability to handle load.

hard-drawn wire

A general purpose carbon steel wire used to make springs. Hard-drawn wire is the least expensive spring wire available and is used only to make springs for low-stress applications.

hardened steel

A carbon steel that has undergone heat treatment, tempering, and quenching in order to change the physical and mechanical properties of the steel. Hardened steel usually has improved hardness and strength.

helical

Having a spiral shape. The helical spring is the most common shape of spring.

helical spring

A type of coil spring formed by winding strips of metal around a cylinder. The helical spring is the most common shape of spring.

helical torsion spring

A type of torsion spring that is spiral shaped. Helical torsion springs are typically subjected to forces that cause them to twist about their axes.

high-carbon steel

A carbon steel that contains more than 0.5% carbon. High-carbon steels are extremely strong and hard.

hinges

A mechanism that allows a door, lid, or gate to swing open. Hinges often use torsion springs to absorb and exert torque.

Hooke’s Law of Elasticity

A rule stating that the distance a spring travels when deflected is directly related to the amount of force exerted upon it. Hooke's Law of Elasticity describes the operation of a linear spring.

hydraulic power

Energy created by the control and motion of liquids under pressure. Hydraulic power can be converted into mechanical energy and used to perform work.

hydraulic spring

A type of spring that is primarily nonmechanical and is powered by pressurized liquids such as oil. Hydraulic springs are sometimes used as automobile shock absorbers.

inner diameter

ID. The distance from one inside edge of a spring's coil to the opposite inside edge that passes through the spring's center and across its face. Inner diameter is a variable that should influence spring selection.

inverted stack

A Belleville-washer stacking configuration in which every other washer is facing the opposite direction. Inverted stacks allow Belleville washers to support greater loads.

kinetic energy

Energy existing due to an object's motion. Kinetic energy is released when a spring deflects and returns to its original shape.

leaf spring

A simple type of spring made of a small, flat piece of metal often used in automotive applications, such as suspension systems. Leaf springs are also called beam springs and flat springs.

left torsion rod

A long, slender, and flexible torsion bar that is often used in cars' trunk lids. A left torsion rod must be used with a right torsion rod.

linear relationship

A connection between two objects in which a change in one object creates an equal change in the other object. Linear relationships include the relationship between the force applied to a linear spring and the force received back from the spring's deflection.

load

The overall force that is applied to a material or structure. Springs absorb and exert energy from loads.

load rates

The speed at which a load is applied to a mechanical component, such as springs and gears, during machine operation. Load rates, which can be static, dynamic, or shock, are one factor in coil spring selection.

mean diameter

D. A measurement of a spring's outer diameter (OD), minus one wire diameter (d). The mean diameter is one of the variables needed when ordering a spring.

mechanical device

A machine component that operates by reacting to and producing force and motion. Mechanical devices, such as springs and gears, help machines perform work.

mechanical power

Energy created by the physical interaction and motion of components. Mechanical power is transmitted through a mechanical system and used to perform work.

mechanical properties

The collection of properties that describe a material's ability to compress, stretch, bend, scratch, dent, or break. Mechanical properties of a material are determined by its molecular structure.

mechanical springs

A type of spring that operates using energy that is created by the physical interaction and motion of components. Mechanical springs include coil springs, flat springs, volute springs, and torsion bars.

mechanical systems

A collection of machines functioning together to perform useful work. All modern mechanical systems are based on simple machines.

motion

A change in an object's original position. Motion is a result of a force applied to an object.

multi-leaf spring

A type of flat spring made by combining pieces of metal. Multi-leaf springs can dampen friction but can accept load in one direction only.

music wire

A high-carbon steel wire used to make springs. Music wire is often available in small diameters and is used to make springs for high-stress applications.

nested stack

A Belleville-washer stacking configuration in which all the washers face the same direction. Nested stacks allow Belleville washers to provide an increased force after deflection.

nitrogen

N. A colorless, odorless, tasteless, naturally occurring gas. Nitrogen exists in the atmosphere and makes up 78% of breathable air.

oil-tempered wire

A general purpose high-carbon steel used to make springs. Oil-tempered wire is less expensive than music wire and is also available in larger diameters.

open ends

A compression spring end coil that is the same as the rest of the spring's coils. Open ends, or plain ends, are not used in safety-critical or important applications requiring a high degree of accuracy.

outer diameter

OD. The distance from one outside edge of a spring's coil to the opposite outside edge that passes through the spring's center and across its face. Outer diameter is a variable that should influence spring selection.

overload stop

A compression spring feature in which the spring's solid compression stops machine support because the spring is overloaded and can no longer safely operate. Overload stop can prevent maintenance personnel injury and machine damage.

permanent set

A type of irreversible deformation that occurs when a spring is subjected to improperly high load conditions. Permanent set prevents springs from operating correctly.

piston

A rod inside a cylinder that is moved by hydraulic or pneumatic pressure. Pistons are often used at high pressure.

plain ends

A compression spring end coil that is the same as the rest of the spring's coils. Plain ends, or open ends, are not used in safety-critical or important applications requiring a high degree of accuracy.

plane

A flat or level surface. A grounded end of a compression spring creates a flat plane.

pneumatic power

Energy created by the control and motion of gases under pressure. Pneumatic power can be converted into mechanical energy and used to perform work.

pneumatic spring

A type of spring that operates using pressurized or compressed gas such as air or nitrogen. Pnuematic springs are sometimes used as automobile shock absorbers.

potential energy

Stored energy with the potential to do work. Springs store potential energy when they deflect loads.

preloading

A procedure used by spring manufacturers to increase the operating capabilities of coil springs. Preloading, or presetting, consists of creating a slightly longer spring than needed and applying an initial amount of load to create some set before shipping it to the customer.

presetting

A procedure used by spring manufacturers to increase the operating capabilities of coil springs. Presetting, or preloading, consists of creating a slightly longer spring than needed and applying an initial amount of load to create some set before shipping it to the customer.

pressurized

To produce or maintain a rise in the continuous physical force exerted on or against an object by something in contact with it. Pressurized liquids and gases have a physical force that is produced or maintained artificially.

right torsion rod

A long, slender, and flexible torsion bar that is often used in cars' trunk lids. A right torsion rod must be used with a left torsion rod.

service life

The length of time a machine or machine component is expected to be in operation before being replaced. The service life of a spring is usually determined by the number of times it deflects.

set

The loss of length in compression springs that occurs due to the stress of deflecting. Compression springs should experience no more than 2% set.

shearing

Damage that occurs when a spring breaks. Shearing occurs when a spring is subjected to a heavy load causing excess transverse, or perpendicular, strain.

shock absorbers

A device, commonly used in vehicles, that absorbs excess vibrations. Shock absorbers commonly consist of a mechanical spring supported by a hydraulic or pneumatic spring.

shock load

A type of load that occurs at extreme speed and exerts tremendous amounts of force. The presence of shock loads affects spring design and selection.

shot peening

A procedure used by manufacturers to increase the operating capabilities of metals used in components. Shot peening is accomplished by blasting metal surfaces with small particles that increase the material's strength and ability to withstand different types of damage.

single-direction torsion spring

A type of torsion spring that accepts load in either a right- or left-hand direction. When ordering single-direction torsion springs, it is important to know the direction of torque transmission that an application requires.

solid compression

The length of a compression spring when fully compressed. The solid compression length is necessary to know when ordering a compression spring.

specifications

A description of the essential physical and technical properties of a machine or device. Specifications set the limits of acceptable deviation for a part's intended application.

splines

Teeth added to shafts and interconnecting components that ensure they move together. Splines fit loosely and provide flexible movement for many devices.

spring

An elastic device used to dampen and apply force, control motion and vibration, and store energy. Springs are used in many mechanical systems to aid in the storage and transfer of energy.

spring rates

The amount of force necessary to deflect a spring 1.0 inch (2.5 cm). Spring rate is often expressed as load per inch (ld/in.) or load per centimeter (ld/cm).

spring washer

A simple component used with screws and other fasteners to provide flexibility and reduce stress. Spring washers come in many sizes and shapes, including flat, helical, and conical shapes.

squared and grounded ends

A compression spring end coil that is flattened and almost completely contacting the next coil. Squared and grounded ends, or closed and grounded ends, allow for better load transfer but are the most expensive type of end coil.

squared ends

A compression spring end coil that is cut to provide almost direct contact with the next coil. Squared ends, or closed ends, improve a compression spring's ability to handle load.

stamping presses

A machine tool with a ram that moves up and down continuously to cut and shape sheet metal using a die set. Stamping presses are most often used for separating scrap and parts from sheet metal during continuous manufacturing operations.

static load

A type of load that maintains the same direction and degree of force during operation. The presence of static loads affects spring design and selection.

steel

A metal consisting of iron and carbon, usually with small amounts of manganese, phosphorus, sulfur, and silicon as well. Steel is the most common manufacturing metal.

steering axles

A shaft upon which a vehicle's wheels are mounted that allows the wheels to turn. Steering axle applications often use flat springs.

strengths

A spring's ability to resist outside forces forces that attempt to bend, stretch, or compress it. If the strength of a spring does not match the conditions under which it operates, the spring may quickly fail.

stress

A force that attempts to deform an object. Deflection is a source of stress for springs.

stress fractures

A hair-like crack that appears on the surface of a spring if the material has been exposed to excess tensile or shear stress. Stress fractures often lead to spring failure.

stress resistance

The ability of a material to resist a force attempting to physically deform it. Stress resistance is an important material property of spring wire.

suspension systems

The components that connect a vehicle's body to its wheels. Suspension system components include springs, shocks, and tires.

tempered

To reheat a metal to intermediate temperatures and then gradually cool it in order to harden the metal's outer surface. Tempered metals usually have improved toughness.

tensile load

A force that attempts to pull apart or stretch an object. Tensile loads are supported by extension, or tensile, springs.

tensile spring

A type of spring designed to support tensile, or pulling, loads. Tensile springs are also called extension springs.

tensile springs

A type of spring designed to support tensile, or pulling, loads. Tensile springs are also called extension springs.

tensile strength

A material's ability to resist forces that attempt to pull it apart. Tensile strength is the amount of tensile stress a material can withstand before fracturing.

torque

A force causing rotation. Torque attempts to twist or rotate an object.

torsion bar

A very simple type of spring consisting of a bar that deforms slightly when loaded. Torsion bars are often used in car suspension systems.

torsion key

A moving control arm attached to one end of a top torsion bar in a car's suspension system. The torsion key swings up and down as the car's wheels move.

torsion load

A type of load that causes objects to twist due to torque. Torsion loads are supported by torsion springs.

torsion spring

A type of spring that transmits torque in machines. Torsion springs can transmit torque by bending in one or two directions, depending on the type of torque needed.

torsion spring

A type of spring that transmits torque in machines. Torsion springs can transmit torque by bending in one or two directions, depending on the type of torque needed.

torsion spring rate

The amount of force generated when a torsion spring rotates one full circle, or one 360° turn. Torsion spring rate is often measured using the inch-pound or foot-pound or using the Newton-meter.

unloaded

Not in the process of experiencing a load or deflecting. Unloaded springs' coils are separate from each other.

volute spring

A type of spring formed by wrapping strips of metal inside each other to create a conical shape with all pieces touching. Volute springs have coils that touch, making them more stable and more expensive than coil springs.

wire diameter

d. The width of the spring wire from one outside edge of the wire to the opposite edge that passes through the wire's center and across its face. Wire diameter is a necessary variable for determining a spring's mean diameter.

working range

The range of operating conditions within which springs can function without becoming permanently deformed. Working range is affected by the speed of operation and the amount and type of load supported.