Product Groups

Merchant Bars and Boron Flat Bars

Merchant Bars and Boron Flat Bars

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STOMANA INDUSTRY SA is the leading manufacturer of merchant bars in Bulgaria. The prestige of STOMANA INDUSTRY's name, the internationally certified quality of merchant bars (TUV Rheinland Group), the manufacturing know-how and flexibility, the large distribution network and the high quality services provided by STOMANA through its representatives, are some of the advantages that make STOMANA the company with the leading market share in Bulgaria.

 

Boron Flats are manufactured at STOMANA SA’s plant in Bulgaria.

 

Boron steel flat bars are used to applications where high strength, good bendability and weldability is required. They also offer good impact toughness and high yield strength. Hot-Rolled Boron Flats are used in the fork-lift industry and especially in the production of forks.

 

Common steel grades are the 15B35 and the 35Mn5 modified.

 

Bars are delivered in width from 80mm to 180mm and in thicknesses from 25mm to 90mm / Length: from 6 to 12m.

HOT ROLLED BORON FLATS
TYPE Hot-Rolled Bars of rectangular cross-section (Flats)
STEEL GRADE RSt 37-2 according to DIN 17100 (S235JR according to EN10025)
RSt 44-2 according to DIN 17100 (S275JR according to EN10025)
15B35 Modified (see below)
35Mn5 Modified (see below)
FORM-DIMENSIONS Straight bars with Width form 80 to 180 mm, and Thickness from 25 to 90 mm
LENGTH - TOLERANCES Bar length: 6 to 12 m with +/- 75 mm tolerance
PACKING - WEIGHT Bundles. Weight up to 5,200 Kg per bundle
DIMENSIONS, WEIGHT&TOLERANCES According DIN 1017
MERCHANT BARS
Type STOMANA INDUSTRY Plant Pernik, Bulgaria SIDENOR SA Plant Thessaloniki, Greece (*)
SQUARES --- Side length from 10 to 40mm
FLATS Width from 80 to 180mm
Thickness from 40 to 90mm		 Width from 20 to 150mm
Thickness from 5 to 20mm
ROUNDS Diameter from 40 to 120mm Diameter from 10 to 40mm
EQUAL ANGLES Leg length from 60 to 100mm
Leg thickness from 6 to 12mm		 Leg length from 20 to 50mm
Leg thickness from 3 to 6mm
IPE BEAMS --- Section height from 80 to 120mm
UPN CHANNELS Section height from 80 to 140mm Section height 30mm
Steel Chemical Composition
Steel Grade C (%) Mn (%) Si (%) Cr S (%) max P (%) max B (%)
RSt 37-2 0.20 max 1.40 max -   0.045   -
RSt 44-2 0.21 max 1.40 max -   0.045   -
15B35 Mod. 0.27 - 0.35 1.00 - 1.60 0.15 - 0.35 0.25 - 0.65 0.025 0.020 0.0005 - 0.0050
30Mn5 Mod. 0.30 - 0.34 1.25 - 1.50 0.15 - 0.35 0.30 - 0.50 0.020 0.025 0.0005 - 0.0040
Mechanical Properties
Steel Grade Nominal Thickness (mm) Sample Yield Strength (N/mm2) min Tensile Strength (N/mm2) Elongation 5d0, (%) Charpy -V- Notch Impact - j (test at -20° C)
RSt 37-2 24-40 as rolled 225 340-470 26 -
  41-63 as rolled 225 340-470 25 -
  > 63 as rolled 215 340-470 24 -
RSt 44-2 25-40 as rolled 265 410-540 22 -
  41-63 as rolled 255 410-540 21 -
  > 63 as rolled 245 410-540 20 -
15B35 Mod. 25-90 quenched & tempered 827 950 min 12 27 j min
  25-90 as rolled - 700 min - -
30Mn5 Mod. 25-90 quenched & tempered 750 900-1,100 - 27 j min
Hardenability, HRC
Steel Grade Thickness (mm)   1.5 5.0 9.0 13.0 15.0 20.0 25.0 30.0 35.0
15B35 Mod. Up to 50 max 58 - - 55 - 50 - - -
15B35 Mod. Up to 50 min 51 - - 41 - 33 - - -
15B35 Mod. 51-71 max 58 - - -   53 - - -
15B35 Mod. 51-71 min 51 - - -   33 - - -
15B35 Mod. > 70 max 58 - - -   55 51 - -
15B35 Mod. > 70 min 51 - - -   41 34 - -
30Mn5 Mod. 25-90 max 55 55 54 53 52 48 44 39 36
30Mn5 Mod. 25-90 min 47 46 42 36 33 27 23 20 -
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