# Flat Bar for Fabrication and What to Check Before Ordering > Source: https://www.unitedsteel.com.au/flat-bar-for-fabrication-and-what-to-check-before-ordering/ > Author: wes towers > Date: 2026-10-07T05:13:59+00:00 Steel flat bar is a versatile product used across construction, manufacturing and general fabrication. Its simple rectangular profile makes it suitable for everything from brackets and supports to machinery components and custom steelwork. However, choosing the right flat bar involves more than selecting a width and thickness. The steel grade, required lengths, finish, and any processing requirements can all affect how the material performs and how efficiently it can be fabricated. Understanding these considerations before ordering can help avoid unnecessary delays, reduce waste and ensure the material supplied meets your project’s requirements. ## What is steel flat bar? Steel flat bar is a solid, rectangular steel section with a consistent width and thickness along its length. Unlike steel hollow sections, flat bar has no hollow interior. Its relatively simple shape makes it convenient to cut, drill, weld and incorporate into fabricated components. United Steel supplies flat bar as part of our [merchant bar range](https://www.unitedsteel.com.au/products/merchant-bar/), alongside round bars, square bars and equal and unequal angles. These products are used across construction, manufacturing, infrastructure and general fabrication, with different sizes and specifications available to suit project requirements. ## Common applications for steel flat bar One of the main advantages of steel flat bar is its versatility. Its flat surfaces and rectangular profile make it a practical choice for fabricated components where a consistent width and thickness are required. Common applications include: - Brackets, mounting plates and connection components - Machinery frames and equipment supports - Fabricated gates, frames and general metalwork - Reinforcement and strengthening components - Custom steel fabrication projects Flat bar can be cut into shorter lengths, drilled for fixings or welded into larger assemblies. For example, a fabricator producing equipment brackets might select flat bar that can be cut to length, drilled and incorporated into the finished assembly. However, the required dimensions and steel grade should always be determined by the intended application, particularly when the component has a structural function. ## Understanding steel flat bar sizes Flat bar is generally specified by its width and thickness, with the required length confirmed separately. For example, a 50 × 10 mm flat bar has a nominal width of 50 mm and a nominal thickness of 10 mm. This is an example of how flat bar dimensions are expressed, rather than confirmation of a particular stock size. When reviewing flat bar sizes, there are three main measurements to consider. Width: The distance across the broad, flat face of the bar. Thickness: The distance between its two broad faces. Length: The overall length required for the finished component or supplied material. It is also important to consider the manufacturing tolerances permitted by the relevant product standard. Where components must fit together precisely, fabricators should confirm whether further machining or finishing will be required. ## Choosing the right steel grade Steel grade is another important consideration when ordering flat bar. Different grades have different mechanical properties, which can affect their suitability for structural applications, welding and other fabrication processes. United Steel’s merchant bar products are supplied to meet the relevant requirements of AS/NZS 3679.1, which covers hot-rolled structural steel bars and sections. For engineered components, the grade should be confirmed against the approved drawings and project specifications. It is also worth checking whether material certification or traceability documentation is required. Providing these details when requesting a quote helps ensure the correct product is identified from the outset. ## Consider your cutting and processing requirements Flat bar is often purchased for further fabrication, making processing requirements an important part of the ordering process. Before ordering, consider whether the material needs to be supplied in standard lengths or cut to specific dimensions. For example, ordering material in suitable lengths may help reduce unnecessary cutting and offcuts during fabrication. United Steel’s [steel processing capabilities](https://www.unitedsteel.com.au/services/steel-processing/) include equipment such as bandsaws for cutting steel sections and other products. If your project requires cut lengths or other processing, discussing these requirements with our team can help establish the available options before placing an order. Providing accurate drawings, dimensions and quantities at the enquiry stage can also make it easier to coordinate the material supply with your fabrication schedule. ## What about the finish? The required finish will depend on how and where the flat bar will be used. For components installed outdoors or in corrosive environments, additional surface protection may be necessary. If the finished component will be welded, painted or galvanised after fabrication, these requirements should be considered when selecting the material and planning the work. Confirming the intended finish early can help avoid unnecessary preparation or rework later. ## Ordering steel flat bar from United Steel Whether you need flat bar for a small fabrication job or an ongoing manufacturing project, providing clear specifications is the first step towards a straightforward ordering process. Before contacting our team, it helps to have the required dimensions, grade, lengths, quantities and any processing requirements ready. United Steel supplies merchant bar products to customers across Australia, supported by an extensive supplier network and steel processing capabilities. [Contact United Steel](https://www.unitedsteel.com.au/contact-us/) to discuss your steel flat bar requirements and find out how our team can support your next fabrication or construction project.