Steel Company

Specialized manufacturing and sales for special steel blooms.

The Steel Company specializes in the manufacture and sale of special steel blooms, which have much stricter quality requirements than other iron and steel products. Through our customers around the globe, including major rolling and forging manufacturers, our products are ultimately used in important fields such as industrial machinery, construction machinery, automobiles, and ships.
With an expertise in special steel, such as alloy steel for machinery structures and carbon steel, we make five types of blooms, such as 390 mm x 500 mm rectangles or circles with a diameter of 500 mm.

For the manufacturing process, we use the latest element technology of the direct current electric furnace, then the secondary refining furnace, and finally the bloom continuous casting equipment, and have an annual output of 220,000 tons.
Our competitiveness is characterized first by over 30 years of experience and accumulation in special steel manufacturing technology, as well as an environment where we can obtain good raw materials (steel scrap) at a low cost and in large quantities, due to the neighboring locations of automobile and shipbuilding industries.

NEWIt specializes in manufacturing and sales of special steel bloom.
Chromium Molybdenum 500mmφ Round Steel Bloom

We have updated the continuous casting gas cutting machine of Hiro Works on November, 2019, and its workability and the section quality of steel bloom has improved.

We would be able to meet the request of the customers, in the condition such as order lot, the deadline on 500mmφ steel bloom production, which were limited in the past.

Torch Car
Chrome Molybdenum Steel (500mmφ.) acroscopic structure of cross-section

Features and Advantages of 500mmφ Round Bloom

Features of quality


Variety of Products

Bloom Size

Nominal Size Nominal Unit Weight Size Tolerance Standard Length Short length Length Tolerance
Height x Width Kgw/m H X W Length Frequency
500mmΦ 1,530 ±10mm 5,500mm 3,500mm 3 pcs or less / 70MT ±100mm

Qualty Assurance/Certification

ISO9001:2015/JIS Q 9001:2015 Certificate No. 4528, Design, development and manufacture 0f specialty steel Blooms by Continuous Casting

Typical Usage and Material Standard

Contract, Quality Assurance etc.

About existing products

Please refer to the followings for existing products other than chrome molybdenum steel.

  1. Mainly produce alloy steel and carbon steel used in key industrial fields.
  2. Utilize 70t EAF and fine scrap sources, we have advantage at small lot production of special steel.
  3. Owing to the wealth of experience and precise work, we guarantee less dispersion of quality.
  4. Short delivery, quick response and high cost competitiveness.
  5. Five size molds including 390mm×500mm rectangle type and 500mmΦ round type.

Business Foundation

  • EAF and secondary refining facilties suitable for alloy steel production, which meets various customer’s quality request.
  • Good location for collecting fine scraps from automotive companies and ship building yards.
  • Compact mill of one strand CC suitable for small lot short delivery production.
  • Business model of cost minimum system.
  • Experience of the special steel manufacturing technology over 30 years.

Variety of Products

Steel Type Usage Standard of steel materials
Specification (JIS No. name) JIS code ASTM,AISI,SAE,and etc.
Alloy Steel Machine Structure JIS G4053 Low-alloyed steels for machine structural use  
(Cr-Mo Alloy Steel)
SCM415, 420, 430, 435, 440(*1), 445
AISI4130, 4140, SAE4130, 4150
(Ni-Cr-Mo Alloy Steel)
SNCM220, 420, 431, 439(*1)
SAE8620, AISI8630M, SAE4340, 17CRNIMO6, 18CRNIMO7-6
(Cr-Ni Alloy Steel) 15CRNI6
(Cr-Alloy Steel)  SCr420 5120
(Mn-Alloy Steel) SAE1541
(Cr-Mo-V Alloy Steel and etc.) 42CrMo4NI, 21CRMOV511
JIS G4052 Structural steels with specified hardenability bands
SCM415H, 420H, 435H, 440H, 445H
Others Forged or Rolled Alloy Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service ( Cr-Mo Steel ) A182F11, A182F12, A182F22
Carbon Steel Machine Structure JIS G4051 Carbon steels for machine structural use
S10C , S15C, S20C, S22C, S25C, S28C, S30C, S35C, S38C, S43C, S45C(*1), S48C, S53C, S55C

SAE1022, 1026, 1045
Free Cutting Steel JIS G4804 Sulphur Free Cutting Steels
SUM22(*1), SUM43
Wire Rod JIS G3505 Low carbon steel wire rods
JIS G3506 High carbon steel wire rods
SWRH27, SWRH37, SWRH42, SWRH47~62
JIS G3507-1 Carbon steels for cold heading-Part 1: Wire rods
(Pipes,Structure, Forging,Shipbuilding, and etc.)
(Carbon Steel Forgings for Piping Applications) A105
(Carbon and Low-Alloy Steel Forgings, Requiring Notch Toughness Testing for Piping Components) A350
(Carbon and Alloy Steel Forgings for Pipe Flanges, Fittings, Valves, and Parts for High-Pressure Transmission Service) A694F52, F60、F65
JIS G3101 Rolled steels for general structure SS400, SS490 A36
JIS G3106 Rolled steels for welded structure SM490A, B
(EN Spec. Weldable Fine Grain Structural Steel) S355NL
E5402 (Railway rolling stock / Solid wheel) SSWR1
(Classification Society std.) S30MN

(*1) [Reference] Chemical composition of typical alloy and carbon steel (wt.%)

Spec.(Sample) C Si Mn P S Ni Cr Mo
SCM440 0.38-0.43 0.15-0.35 0.60-0.90 ≦0.030 ≦0.030 ≦0.25 0.90-1.20 0.15-0.30
SNCM439 0.36-0.43 0.15-0.35 0.60-0.90 ≦0.030 ≦0.030 1.60-2.00 0.60-1.00 0.15-0.30
S45C 0.42-0.48 0.15-0.35 0.60-0.90 ≦0.030 ≦0.035 - - -
SUM22 ≦0.13 - 0.70-1.00 0.07-0.12 0.24-0.33 - - -

Manufacturing Process and Main Facilities

Process Main Facilities Function
Basket Blending
Radio Isotope Check
Portable Chemistry Check
・Precise Blending to Meet Specifications
70ton EAF ・Melting, Reduction of Impurity and Inclusions
・Addition of Alloy Elements
Secondary Refining
Ladle Refining & Degassing (LF-V) ・Vacuum Degassing(H,O,N)
・Reduction of Inclusions
・Chemistry Adjustment
Continuous Casting

15mR Continuous Caster
Mold EMS
Air-Mist Spray
・Floating Non-Metal Inclusions
・Diminishing Central Segregation
・High Surface Quality
Cutting & Cooling
Straightening, Cutting, Cooling Slow Cooling
(For Fragile Alloy)
・Crack Prevention, Surface Visual Inspection, Etching Inspection
・Dehydrogenation by Insulation Cover Pit
Shipping & Delivery Land Transport
Marine Transport
(Private Wharf)
・Transportation by Truck & Trailer
・Shipping by Container Ship or Bulk Carrier

Bloom Size

Nominal Size Nominal Unit Weight Size Tolerance Length
Standard Length Short length Length Tolerance
Height x Width Kgw/m H X W Length Frequency
390x500mm 1,530 ±10mm 5,500mm 3,500mm 3 pcs
or less
/ 70MT
500mmφ 1,530 5,500mm
348x423mm 1,145 6,500mm
300x400mm 940 6,500mm
245x245mm 470 5,000mm 4,500mm

Qualty Assurance/Certification

ISO9001:2008/JIS Q 9001:2008 Certificate No. 4528, Manufacturing Blooms by Continuous Casting
Class NK :Approval No. ST367CF / Certificate No. TA16815E, Carbon Steels, Low-Alloy Steels

Typical Usage of Products

Processing at Customer Typical Usage
Rod & Wire Rolling for Rods & Wires [Construction/ Machine] Large Diameter Ring, Ring Gear, Bearing Race, Folk and etc.
[Ship] Crank Shaft, Gear, Flange, Hook, Railway Solid wheel
[Plant] Pipes, Elbow, others
Forging Free Forging, Die Forging, Roll Forging and etc.
Pipes & others Piercing Rolling, Plate Rolling and etc.

Contract, Quality Assurance and etc.


Head Office / Steel Division

Zip Code 160-0022 Ohashi Gyoen-Eki Building 2F
1-8-1 Shinjuku, Shinjuku-ku Tokyo Japan

Hiro Works / KOTOBUKI Steel Co.,Ltd.

Zip Code 737-0144
1-2-43 Hiroshiratake Kure-Shi Hiroshima Japan