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    Material Unibar 300

    Unibar 300

    Grade Colour Code: Red
    Grey/Flake Iron

    Comparative Specification:

    • EN-GJL-300C according to DIN EN 16482
    • EN-GJL-300 according to BS EN 1561 (2011)

    Our grey iron Unibar 300 is alloyed to achieve the specified properties, giving excellent wear resistance, strength and heat-treatment response compared to Unibar 200 and Unibar 250, while still possessing reasonable machinability and an excellent surface finish. Noise and vibration damping are good in this grade.

    Profile and Size Range

    Standard cut length of our cast iron products is 3080mm, other lengths available on request.

    Round Square Rectangle Special Profiles
    25mm – 700mm 25mm x 25mm – 550mm x 550mm Up to 780mm x 550mm Sizes and profiles to customer design available on request

    Mechanical Properties

    Material Section mm Tensile Strength
    20 < D ≤ 50 220 190 - 260 Predominantly Pearlitic
      50 < D ≤ 100 205
    100 < D ≤ 200 195
    200 < D ≤ 400 185
    400 < D ≤ 700 185


    Contains type ‘A’ graphite flakes in accordance to ISO 945. The rim zone contains fine types ‘D’ and ‘E’ interdendritic graphite. The core matrix is greater than 90% pearlite. The rim matrix is ferrite/pearlite mixture. The rim may contain up to 5% dispersed fine carbides.

    Heat Treat Response

    Unibar 300 is suitable for all conventional methods of heat treatment, with hardness levels of up to Rc 50 achievable.

    Ancillary Processes

    Both, our foundries and our local distribution centres offer various services to deliver pre-machined products to our customers. Pre-machined Unibar material will save valuable production time, improve the cost effectiveness and eliminate waste in your own production, allowing you to focus on the key design elements of your products.


    Cutting to specified length in quantities as little as one piece to large volumes, prepared to meet the requirement of your automatic machining systems.


    Turning of round bars to required size to meet specific requirements and to minimise the machining operations of our customers. Unibar turned therefore comes with a standard tolerance of +1mm, although after consultation we can offer alternatives to suit all of our customers‘ requirements.


    Single and duplex machines offer milling of square and rectangular bars to specified dimensions and agreed tolerances. We can offer our customers milling on either four or six faces for further processing.


    In the case of machined Unibar with diameters of less than 110mm as an alternative to Unibar turned we can offer Unibar peeled by peeling off the oxidised surface layer of the cast bar. As these are smaller dimensions and involve a different machining process, the tolerances offered are more precise, for example h11.


    Longitudinal boring as deep as 1000mm is possible by using single head boring and trepanning machines. Unibar tubes can be supplied with the exterior surface as-cast or machined. These two variants can be complemented by a wide selection of internal measurements, which can range from 30mm to 500mm.

    Dimensional Tolerances (Grey/Flake)

    (As-Cast Diameter mm)
    Ovality Allowances
    Max. Swell Allowances mm
    20 < (D OR B) ≤ 50 - 5
      50 < (D OR B) ≤ 100 1 7
    100 < (D OR B) ≤ 200 2 10
    200 < (D OR B) ≤ 300 4 12
    300 < (D OR B) ≤ 400 5 15
    > 400 By agreement By agreement

    Machining Allowances (Grey/Flake)

    (D Diameter, B Width)
    Min. Machining Allowance mm (per side)
    Round Square/Rectangle
    20 < (D OR B) ≤ 50 2 2.5
      50 < (D OR B) ≤ 100 3 3.5
    100 < (D OR B) ≤ 200 4 4.5
    200 < (D OR B) ≤ 300 6 6.5
    300 < (D OR B) ≤ 400 7 7.5
    400 < (D OR B) ≤ 500 9 9.5
    500 < (D OR B) ≤ 650 11 11.5

    For rectangular bars the width is the longer dimension of the cross section. Machining allowances of our continuously cast iron bars can be adjusted to meet customer requirements, subject to discussion, prior agreement and special order. For further information please contact our nearest distribution centre.


    Unibar 300 is particularly used for different applications within the hydraulic and pneumatic or the machinery and machine tool industries, in the automotive sector, for pumps and compressors, in the oil and gas industry as well as for the steel machinery.

    Due to its structure and the mechanical properties Unibar 300 is a profitable alternative to other materials such as steel, aluminium or traditional sand casting.


    • Improved machinability
    • Excellent surface finish
    • 10% weight reduction against steel
    • Excellent vibration damping
    • Faster turning and grinding times
    • Finer grain structure than with sand casting
    • Absence of sand inclusions or cast dimensional problems
    • Elimination of costly patterns
    • Availability from stock

    Do you need any further information about our continuously cast iron products? You will find the appropriate data sheets as well as our technical manual in our download section.

    To find out whether Unibar 300 is available in your required size, please have a look at our online stock list. Register and keep track of the currently available quantities.