Hot-rolled Flat Bar
to spec EN10025: 2004 S275JR+AR
W – Width
T – Thickness
Kg/m – Kilos per linear metre
L – Standard bar length
Contact Harris Steels if you would like to request a price, place an order, or have any further questions about our Hot-rolled Flat Bar steel stock range.
About this product
Hot rolled flat bar (sometimes referred to as long products, re-rolled and merchant bar) is a versatile low cost, low carbon product suitable for a great variety of applications. The low carbon content (0.22% max) and low yield point (275N/mm² min) of the steel enable easy forming, fabrication and machining processes to be carried out without the need for specialist tooling requirements or heat treatments.
The outside of the bar in the AR (as rolled) condition has a blue/grey coloured finish, this is known as the surface scale and can be removed by pickling and oiling (P&O) or various abrasives including shot blasting. The scale also provides a limited protection against light corrosion, this is often more visible during the warmer months due to a rapid temperature change post shot blasting. Condensation can form and react with the steels iron content and form rust discoloration.
All products are manufactured to production tolerances and hot rolled products are no exception. A billet or bloom is heated to around 1200°C and fed through a series of different rolls including roughing, intermediate and finishing. These rolls reduce the cross sectional area and conversely increase the billet or bloom length. The shape and specification dimensions of the section is also produced at this stage. From leaving the furnace at 1200°C the material is cooling down and will eventually pass through the finishing rolls at around 900°C, the rate of cooling is critical to the properties of the steel and suitability for application.
Due to the significant temperature reduction to cold and with no subsequent finishing before end use, it is not possible to precisely control the section tolerances during hot rolling. Tolerances vary depending on the size of section but are typically 0.4 mm up to millimetres on larger sections. Bright drawn, peeled and ground take over where tighter tolerances of less than 0.2 mm are required.
Hot rolled flat bars are generally available in 6 metre lengths only, however the smaller flats (often called baby flats) with a 3 mm thickness are available in 4 metre lengths. For larger orders we can have bars rolled to bespoke customer lengths to minimise scrap and offer considerable cost savings.
BS EN10025:2004 S275JR+AR
10 x 3 mm up to 300 x 20 mm