Black Steel Tolerances
Black Steel Tolerances
Width Tolerance for Black Flats
Width in mm | Tolerance in mm |
20mm to 35mm | + / - 0.75mm |
40mm to 70mm | + / - 1.00mm |
80mm to 100mm | + / - 1.50mm |
120mm | + / - 2.00mm |
150mm | + / - 2.50mm |
150mm and above | + / - 2% of nominal width but shall not exceed 10mm |
Thickness Tolerance for Black flats up to 150mm wide
Width in mm | Tolerance in mm |
Up to 20mm | + / - 0.50mm |
20mm to 40mm | + / - 1.00mm |
40mm and over | + / - 1.50mm |
Thickness tolerance for flats over 150mm wide
Width in mm | Tolerance in mm |
4mm to 10mm | + / - 0.05mm |
10mm to 20mm | + / - 0.06mm |
20mm to 25mm | + / - 0.07mm |
25mm to 30mm | + / - 0.08mm |
30mm to 40mm | + / - 0.09mm |
40mm to 50mm | + / - 1.00mm |
50mm to 60mm | + / - 1.10mm |
60mm to 80mm | + / - 1.30mm |
80mm and over | + / - 2.00mm |
Tolerances on Black Hot Rolled Square Bars
Size in mm | Tolerance in mm |
8mm to 14mm | + / - 0.40mm |
14mm to 25mm | + / - 0.50mm |
25mm to 35mm | + / - 0.60mm |
35mm to 50mm | + / - 0.80mm |
50mm to 80mm | + / - 1.00mm |
80mm to 100mm | + / - 1.30mm |
100mm to 120mm | + / - 1.50mm |
Tolerances on Black Hot Rolled Round Bars
Size in mm | Tolerance in mm |
All round bar | + / - 1.30 % on diameter |
Tolerances on Rolled Hollow Sections
Dimension | Tolerance in mm |
Outside dimensions | + / - 1% with a minimum of + / - 0.5mm |
Thickness | + / - 10 % |
Straightness | Shall not deviate by more than 2% of total length measured at the centre of that length. |
Tolerances on Black Mild Steel Angle
Dimensional Tolerances
Leg Length mm | Tolerance in mm |
Up to and including 50mm | + / - 1.00mm |
Greater than 50mm up to and including 100mm | + / - 2.00mm |
Greater than 100mm up to and including 150mm | + / - 3.00mm |
Greater than 150mm up to and including 200mm | + / - 4.00mm |
Greater than 200mm | + 6.00mm / - 4.00mm |
Thickness Tolerances
Section Thickness mm | Tolerance mm |
Up to and including 5mm | + / - 0.5mm |
Greater than 5 up to and including 10mm | + / - 0.7mm |
Greater than 10 up to and including 15mm | + / - 1.00mm |
Greater than 15mm | + / - 1.20mm |
Chemical and Mechanical Tolerances for 43A and 43C (or derivatives)
BSEN10025 S 275JR/ BS4360 43A/ EN10025 FE430 A/ B
MAXIMA | |
Carbon | 0.250% |
Silicon | 0.500% |
Manganese | 1.600% |
Phosphorous | 0.050% |
Sulphur | 0.050% |
Yield Stress (Y.S.) | > 275 N/mm2 |
Ultimate Tensile Strength | 430 / 470 N/mm2 |
% Elongation | > 23% |
BS6363 1983 GRD 43/36 BS4360 43C Box Section
MAXIMA % | |
Carbon | 0.180% |
Silicon | 0.50% |
Manganese | 1.500% |
Phosphorous | 0.040% |
Sulphur | 0.040% |
Yield Stress (Y.S.) | > 225 N/mm2 |
Ultimate Tensile Strength | 430 / 580 N/mm2 |
% Elongation | > 22% |