Scott Precision Wire Ltd manufactures flat wire products in a large range of sizes and different alloys and can supply them in a number of different packaging formats, all to suit a customer’s requirements. Every product is made to our customer’s unique specification, against their order and as such our processes are highly customisable. Stock of round wire is rolled flat to order. If you have a unique need, please challenge us to meet it.
Flat wire is also known as ribbon or rolled wire and is generally dimensionally smaller than strip. Strip is generally slit to size from a coil of flat material and tends to have sharper edges than rolled flat wires.
Flat wire is typically used in applications from small battery leads, to boiler flame out detectors, to leaf springs, to bi-metallic strips, to mechanical components such as those used in watch mechanisms, to electronic circuit board components, to electrical components such as plug and socket pins. They are also used in mesh and filter type products where some mechanical stability is required.
A large application for rolled flat wire is to manufacture thermocouple electrical connector pins where the material needs to be the same as the thermocouple lead material to prevent causing deviations in EMF readings. Thin, rolled flat thermocouple wire is relatively flexible which allows for good contact between pin and socket.
Flat wires can be plastic coated to form a cable and provide electrical insulation or mechanical protection – call us with your specification.
The range of products that can be supplied vary from hard alloys, such as nickel chrome, stainless steels through to softer, copper nickel, brass, bronze and copper wire alloys. Softer alloys, such as those that are copper based, have marginally lower manufacturing costs as they can be run faster through the production line and invariably only require one pass to achieve the desired sizes.
Flat wires can be supplied in a soft annealed condition or a hard, as rolled condition. Hard flat wires are marginally lower in cost as they miss out the annealing process.
The Manufacturing Process –
Flat wires are rolled between two sets of large super hard cylindrical rollers, inline, to achieve the finished flat profile and dimensions. The rollers are hydraulically pushed together under pressure, leaving a small gap through which the wire is reduced in size. The subsequent flat wire dimensions are extremely consistent and small tolerances can be achieved. The speed of rotation of the rollers is critical and is controlled to match the linear speed of the wire
passing between the rollers, thus preventing roller slip that can cause premature roller wear and mark the surface of the flat wire.
Flat wires originate as circular wires and have slightly rounded ends avoiding the problems of deformed or rough edges and burrs associated with slitting. This makes them ideal for such applications as electrical connector pins. Choosing the correct wire diameter is important to the finished wire size as the volume of material per linear length is the same in round (pre-flattened state) to the flat wire (post-flattened state) as the wire isn’t stretched or compressed during the flattening process.
All our flat wires pass through an in-line dimension measuring machine on the production line, where width and thickness are recorded giving our customers confidence that every meter is dimensionally the same. The in-line measuring equipment allows an exact length of flat wire to be produced in metric m or imperial feet.
During the manufacturing process a small amount of lubricating oil is applied to the wire to improve the rolling process and to prevent roll wear. This oil is cleaned off in an immersed ultrasonic cleaning tank after the wire has been flattened but before it is spooled, but, if required, can be left on the flat wire to help lubricate during the customer’s manufacturing process. If this is of interest please discuss your requirements with our technical team by using the ‘Contact us’ button.
The penultimate part of the process is optional and depends on whether the customer’s specification is to receive softened or non-softened (hard) wire. If softened wire is required, the wire is softened in an annealing process that may use either a single strand electrical heated oven with an inert (gaseous) atmosphere or it may involve using an in-line single strand induction annealing machine. The gaseous atmosphere in the electrical oven may be nitrogen or it may be cracked ammonia, and depends on the alloy being softened. A gaseous atmosphere is used to prevent corrosion / marking on the flat wire surface that can occur at the very high temperatures required to soften the wire. The ‘softness’ of the flat wire is specified as a mechanical tensile strength or a surface hardness and Scott Precision Wire use a computer controlled tensometer to measure the elongation.
The flat wire is then spooled onto reels. There is a wire accumulator used that stores processed wire allowing the rolling line operator to change over reels without slowing or stopping the rolling process, thus ensuring consistently sized material through the production run. A range of reel sizes and types are available – please ask us if you have a specific requirement. Depending on the alloy, reels may be wrapped in cling film or moisture absorbent paper to prevent contaminating the flat wire on the outer surface of the reel.
As part of our commitment to total quality a full test report and certificate can be supplied with each delivery, which can include the thermocouple, electrical, dimensional, hardness and tensile properties of the material against the customer’s specification. The certification can include traceability back to the original melt certificate from the alloy producer.
Call us with your requirements, you won’t be disappointed!