The specific type of metal wire that you choose for your projects can significantly impact the viability of your product. Different compositions offer varying levels of strength, toughness, magnetism, and corrosion resistance that all need to be weighed based on the factors of the intended product application. It’s critical to select a wire material that will offer the best functionality and the most optimal service life.
Metal wire is used in a wide range of products, including:
Steel wire needs to be carefully selected, as it is available in multiple grades with differing properties. There are two main considerations that influence these properties, the first being the chemistry or “recipe” of the base metal. This chemistry consideration leads to three broad categories of base metal types: 1) carbon steel grades, 2) alloy steel grades, and 3) stainless steel grades, as detailed further below.
The second consideration is the amount of cold-working that remains after the drawing of the wire, which determines the tensile strength of the wire, also referred to as the temper of the wire. Wire is manufactured by taking hot-rolled wire rod of the desired base metal composition and passing it through one or more diameter-reducing dies at room temperature; this process is known as cold-drawing or hard-drawing. In addition to reducing the diameter and improving the finish and geometry of the round material, each drawing stage increases the tensile strength of the wire, up to some natural limit. The wire in this hardened state is known as “as-drawn” or “hard-drawn.” Intermediate tempers can then be produced by performing a secondary annealing process to soften the wire after drawing. These intermediate tempers are referred to by a variety of terms, such as annealed, quarter-hard, full-hard, spring temper, and others, or by simply specifying a desired final tensile range.
Additional considerations in specifying for a particular wire application include the finish and type of packaging required.
Recapping the above, to specify wire one needs to know base metal, temper/tensile strength, diameter, and finishing and packaging requirements.
Carbon steel grades are so named because their properties are primarily determined by the level of carbon in the base metal.
Low Carbon Bright Basic Steel Wire
Low Carbon Bright Basic Steel Wire is a good general-purpose grade and is the type most commonly seen in everyday life, such as in coat hangers, appliance shelving, store displays, and paper clips. It bends and flattens well, forms shapes easily, and is good for welding. The carbon content of low-carbon bright basic steel wire ranges from 0.06% to 0.20%, but the most commonly available grades are 1008 (0.08% carbon) and 1018 (0.18% carbon). Low Carbon Bright Basic Steel Wire is most commonly furnished in “as-drawn” or “hard-drawn” condition, but Bright Annealed tempers are also available on special request.
Low Carbon Black Annealed Steel Wire
Low Carbon Black Annealed Steel Wire is a coarse grade that is generally used for tie wire. Carbon content is typically 0.06%-0.08% and is furnished fully annealed (full-soft temper). Because of the final annealing step, all protective oils and drawing compounds are cooked off and the wire rusts easily and can be coarse or dirty to the touch.
Medium Carbon Bright Basic Steel Wire
Although not common, Medium Carbon Bright Basic Steel Wire is available as a special mill run, and minimum order quantity can be at least 8,000 lbs. and perhaps greater, depending on the particular chemistry desired. Carbon content ranges from 0.22% to 0.45%.
High Carbon Spring Temper Steel Wires
High Carbon Steel is used for making spring temper carbon steel wires. Commonly available grades of spring steel wire are not furnished with specific chemistry designations such as 1065 or 1080, which is common with other types of high carbon steel products. Rather, they are specified and manufactured according to performance standards targeted to their primary end use, which is the making of coiled springs. These performance standards allow a range of carbon content but have additional factors such as tensile strength and bending/coiling tests that must be met within specified ranges.
There are three primary categories of high carbon spring steel wire:
Hard Drawn Spring Steel Wire
Hard Drawn Spring Steel Wire, also known as HDMB Spring Steel Wire, is a cost-effective option for many general-purpose applications. Carbon content ranges from 0.45% to 0.85%. As it is not typically heat treated after drawing, it exhibits high strength and moderate toughness. It is available in a wide range of diameters and is manufactured in conformance to ASTM A227 for uncoated finishes, and to ASTM A764 for galvanized finishes.
Oil-Tempered Spring Steel Wire
Oil-Tempered Spring Steel Wire, also know as OTMB Spring Steel Wire, is an excellent general-purpose spring wire with improved properties compared to Hard Drawn. Carbon content ranges from 0.55% to 0.85%. After drawing, oil-tempered wire undergoes heat treatment and controlled cooling in an oil bath to increase its toughness while retaining high tensile strength. This makes it especially suitable in applications requiring high impact resistance or high numbers of deflection cycles. Oil-Tempered Spring Steel Wire is available in a wide range of diameters and is manufactured in conformance to ASTM A229. Galvanized finish is not available in this grade.
Music Spring Quality Steel Wire
Music Spring Quality Steel Wire, also known as Music Wire or Piano Wire, is a very high-quality grade for demanding applications. Carbon content ranges from 0.70% to 1.00%. Music Wire is heat treated after drawing to stress-relieve and toughen the wire while retaining high tensile strength. Music wire is generally available in diameters of 0.250” or less and is manufactured in conformance with ASTM A228. It is available in a variety of finishes such as bright, phosphate, tin-coated, and galvanized.
Alloy steel grades are so named because their properties are heavily influenced by alloying elements other than carbon. Although not common, Alloy Steel Wire grades are available as a special mill run and minimum order quantity can be at least 8,000 lbs. and perhaps greater, depending on the particular chemistry desired.
The distinguishing factor of Stainless Steel Wire is its resistance to rust and corrosion in wet or chemical environments. It is often specified in applications such as food service, medical equipment, or any application requiring high levels of corrosion resistance. It is available in many grades and tempers, and a wide variety of diameters. The most commonly available wire grades are as follows.
Type 304 Stainless Steel Wire in Forming Temper
An economical general-purpose stainless grade often used in formed parts, forming temper is generally designated as quarter-hard. Manufactured in conformance to ASTM A580.
Type 302 Stainless Steel Wire in Spring Temper
An economical general-purpose stainless grade used in the manufacture of springs. Manufactured in conformance to ASTM A555.
Type 316 Stainless Steel Wire
A higher-cost grade where higher corrosion resistance is required; available in forming temper and in spring temper. Manufactured in conformance to either ASTM A580 or ASTM A555, depending on the temper specification.
Other grades available upon request.
Steel wire isn’t always suitable for every application. Non-ferrous metals typically offer good corrosion resistance, are non-magnetic, are highly malleable, and often lightweight.
Aluminum is often a good choice for applications that require a good strength-to-weight ratio and is available in multiple varieties, such as:
Copper and copper-clad steel wires are available for applications requiring high electrical conductivity.
Nickel alloy wires are available in different varieties, including Inconel 600 and Monel 400.
At Alabama Wire, we act as a single source for all of your wire requirements. Selecting the most ideal wire solution for your use case may require guidance from experts who can select an appropriate wire material and grade based on the specific details of your application. Our in-house staff is always ready to offer advice and consultation to make sure you get the best possible wire for your needs.
For more information about our available wire products or for help selecting an appropriate wire for your project, please contact us.