Spring steel

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Spring steel is a name given to a wide range of steels [1] used in the manufacture of springs, prominently in automotive and industrial suspension applications. These steels are generally low-alloy manganese, medium-carbon steel or high-carbon steel with a very high yield strength. This allows objects made of sprung steel to return to their original shape despite significant deflection or twisting.

Contents

Grades

Many grades of steel can be hardened and tempered to increase elasticity and resist deformation; however, some steels are inherently more elastic than others:

Common spring steel grades
SAE grade
(ASTM grade)
CompositionYield strengthHardness (HRC)Comments
TypicalMaximum
10700.65-0.75% C, 0.60-0.90% Mn, max .050% S, max .040% PNormally supplied annealed165vpn180vpnCS70, CK67, C70E
1074/1075 [2] 0.70–0.80% C, 0.50–0.80% Mn, max. 0.030% P, max. 0.035% S [3] 62–78 ksi (430–530 MPa) [4] 44–50 [5] 50Scaleless blue,or Polished Bright
1080 (A228) 0.7–1.0% C, 0.2–0.6% Mn, 0.1–0.3% Si [6] Piano wire, music wire, springs, clutch discs
1095 (A684) [2] 0.90–1.03% C, 0.30–0.50% Mn, max. 0.030% P, max. 0.035% S [7] 60–75 ksi (413–517 MPa), annealed48–51 [5] 59Blue, or polished bright spring steel
5160 (A689) [8] 0.55–0.65% C, 0.75–1.00% Mn, 0.70–0.90% Cr [9] 97 ksi (669 MPa)63Chrome-silicon spring steel; fatigue-resistant
50CrV4 (EN 10277)0.47–0.55% C, max. 1.10% Mn, 0.90–1.20% Cr, 0.10–0.20% V, max. 0.40% Si 1200 MPaOld British 735 H1steel, SAE 6150, 735A51
92550.50–0.60% C, 0.70–0.95% Mn, 1.80–2.20% Si [9]
301 spring-tempered
stainless steel [10]
0.08–0.15% C, max. 2.00% Mn, 16.00–18.00% Cr, 6.00–8.00% Ni [9] 147 ksi (1014 MPa)42Equivalents EN 10088-2 1.4310, X10CrNi18-8

Applications

See also

Related Research Articles

High-strength low-alloy steel

High-strength low-alloy steel (HSLA) is a type of alloy steel that provides better mechanical properties or greater resistance to corrosion than carbon steel. HSLA steels vary from other steels in that they are not made to meet a specific chemical composition but rather specific mechanical properties. They have a carbon content between 0.05 and 0.25% to retain formability and weldability. Other alloying elements include up to 2.0% manganese and small quantities of copper, nickel, niobium, nitrogen, vanadium, chromium, molybdenum, titanium, calcium, rare-earth elements, or zirconium. Copper, titanium, vanadium, and niobium are added for strengthening purposes. These elements are intended to alter the microstructure of carbon steels, which is usually a ferrite-pearlite aggregate, to produce a very fine dispersion of alloy carbides in an almost pure ferrite matrix. This eliminates the toughness-reducing effect of a pearlitic volume fraction yet maintains and increases the material's strength by refining the grain size, which in the case of ferrite increases yield strength by 50% for every halving of the mean grain diameter. Precipitation strengthening plays a minor role, too. Their yield strengths can be anywhere between 250–590 megapascals (36,000–86,000 psi). Because of their higher strength and toughness HSLA steels usually require 25 to 30% more power to form, as compared to carbon steels.

Tool steel

Tool steel refers to a variety of carbon steel and alloy steel that are particularly well-suited to be made into tools. Their suitability comes from their distinctive hardness, resistance to abrasion and deformation, and their ability to hold a cutting edge at elevated temperatures. As a result, tool steels are suited for use in the shaping of other materials. With a carbon content between 0.5% and 1.5%, tool steels are manufactured under carefully controlled conditions to produce the required quality. The presence of carbides in their matrix plays the dominant role in the qualities of tool steel. The four major alloying elements that form carbides in tool steel are: tungsten, chromium, vanadium and molybdenum. The rate of dissolution of the different carbides into the austenite form of the iron determines the high-temperature performance of steel. Proper heat treatment of these steels is important for adequate performance. The manganese content is often kept low to minimize the possibility of cracking during water quenching.

Emery (rock) Metamorphic rock

Emery, or corundite, is a dark granular rock used to make abrasive powder. It largely consists of corundum, mixed with other minerals such as the iron-bearing spinels, hercynite, and magnetite, and also rutile (titania). Industrial emery may contain a variety of other minerals and synthetic compounds such as magnesia, mullite, and silica.

Bench grinder Grinding machine

A bench grinder is a benchtop type of grinding machine used to drive abrasive wheels. A pedestal grinder is a similar or larger version of grinder that is mounted on a pedestal, which may be bolted to the floor or may sit on rubber feet. These types of grinders are commonly used to hand grind various cutting tools and perform other rough grinding.

Carburizing Heat treatment process in which a metal or alloy is infused with carbon to increase hardness

Carburising, carburizing, or carburisation is a heat treatment process in which iron or steel absorbs carbon while the metal is heated in the presence of a carbon-bearing material, such as charcoal or carbon monoxide. The intent is to make the metal harder. Depending on the amount of time and temperature, the affected area can vary in carbon content. Longer carburizing times and higher temperatures typically increase the depth of carbon diffusion. When the iron or steel is cooled rapidly by quenching, the higher carbon content on the outer surface becomes hard due to the transformation from austenite to martensite, while the core remains soft and tough as a ferritic and/or pearlite microstructure.

Sheet metal

Sheet metal is metal formed by an industrial process into thin, flat pieces. Sheet metal is one of the fundamental forms used in metalworking, and it can be cut and bent into a variety of shapes. Countless everyday objects are fabricated from sheet metal. Thicknesses can vary significantly; extremely thin sheets are considered foil or leaf, and pieces thicker than 6 mm (0.25 in) are considered plate steel or "structural steel".

The unified numbering system (UNS) is an alloy designation system widely accepted in North America. Each UNS number relates to a specific metal or alloy and defines its specific chemical composition, or in some cases a specific mechanical or physical property. A UNS number alone does not constitute a full material specification because it establishes no requirements for material properties, heat treatment, form, or quality.

SAE steel grades

The SAE steel grades system is a standard alloy numbering system for steel grades maintained by SAE International.

Polishing (metalworking) Abrasive process for creating smooth finished surfaces

Polishing and buffing are finishing processes for smoothing a workpiece's surface using an abrasive and a work wheel or a leather strop. Technically polishing refers to processes that use an abrasive that is glued to the work wheel, while buffing uses a loose abrasive applied to the work wheel. Polishing is a more aggressive process while buffing is less harsh, which leads to a smoother, brighter finish. A common misconception is that a polished surface has a mirror bright finish, however most mirror bright finishes are actually buffed.

Buttress thread

The buttress thread form refers to two different thread profiles:

Steel casting is a specialized form of casting involving various types of steel. Steel castings are used when cast irons cannot deliver enough strength or shock resistance.

Black oxide or blackening is a conversion coating for ferrous materials, stainless steel, copper and copper based alloys, zinc, powdered metals, and silver solder. It is used to add mild corrosion resistance, for appearance, and to minimize light reflection. To achieve maximal corrosion resistance the black oxide must be impregnated with oil or wax. One of its advantages over other coatings is its minimal buildup.

Screw Type of fastener characterized by a thread wrapped around a cylinder core

A screw and a bolt are similar types of fastener typically made of metal, and characterized by a helical ridge, known as a male thread. Screws and bolts are used to fasten materials by the engagement of the screw thread with a similar female thread in the matching part.

Thread angle

The thread angle of a screw is the included angle between the thread flanks, measured in a plane containing the thread axis. This is a defining factor for the shape of a screw thread. Standard values include:

Emery cloth

Emery cloth is a type of coated abrasive that has emery glued to a cloth backing. It is used for hand metalworking. It may be sold in sheets or in narrow rolls, typically 25 or 50 mm wide, often described as "emery tape". The cloth backing makes emery cloth stronger in tension than sandpaper, but still allows a sheet to be conveniently torn to size.

Cemented carbide Type of composite material

Cemented carbide is a hard material used extensively as cutting tool material, as well as other industrial applications. It consists of fine particles of carbide cemented into a composite by a binder metal. Cemented carbides commonly use tungsten carbide (WC), titanium carbide (TiC), or tantalum carbide (TaC) as the aggregate. Mentions of "carbide" or "tungsten carbide" in industrial contexts usually refer to these cemented composites.

Mushet steel, also known as Robert Mushet's Special Steel (RMS) and, at the time of its use, self-hardening steel and air-hardening steel, is considered to be both the first tool steel and the first air-hardening steel. It was invented in 1868 by Robert Forester Mushet. Prior to Mushet steel, steel had to be quenched to harden it. It later led to the discovery of high speed steel.

Conveyor chain

A conveyor chain is chain that has been designed specifically for chain conveyor systems. It consists of a series of journal bearings that are held together by constraining link plates. Each bearing consists of a pin and a bush on which the chain roller revolves.

Waviness is the measurement of the more widely spaced component of surface texture. It is a broader view of roughness because it is more strictly defined as "the irregularities whose spacing is greater than the roughness sampling length". It can occur from machine or work deflections, chatter, residual stress, vibrations, or heat treatment. Waviness should also be distinguished from flatness, both by its shorter spacing and its characteristic of being typically periodic in nature.

Threaded rod

A threaded rod, also known as a stud, is a relatively long rod that is threaded on both ends; the thread may extend along the complete length of the rod. They are designed to be used in tension. Threaded rod in bar stock form is often called all-thread.

References

  1. Engineering.com (23 October 2006). "Springs".
  2. 1 2 McMaster-Carr catalog (116th ed.), McMaster-Carr, p. 3630, retrieved 3 September 2010.
  3. "74-75 Carbon Spring Steel". Precision Steel Warehouse. Retrieved 5 December 2013.
  4. "SAE-AISI 1074 (G10740) Carbon Steel". MakeItFrom.com. Retrieved 21 August 2015.
  5. 1 2 http://www.admiralsteel.com/pdf/catalog.pdf
  6. "ASTM A228 (SWP-A, K08500) Music Wire". MakeItFrom.com. Retrieved 21 August 2015.
  7. "95 Carbon Spring Steel". Precision Steel Warehouse. Retrieved 5 December 2013.
  8. McMaster-Carr catalog (116th ed.), McMaster-Carr, p. 3632, retrieved 3 September 2010.
  9. 1 2 3 Oberg, Erik, and F D. Jones. Machinery's Handbook. 15th ed. New York: The Industrial Press, 1956. 1546–1551. Print.
  10. McMaster-Carr catalog (116th ed.), McMaster-Carr, p. 3662, retrieved 3 September 2010.
  11. Oberg et al. 2000 , p. 286.

Bibliography