Forged Steel Round Bar
High-strength forged round bars manufactured through open-die forging for superior mechanical properties and structural integrity.
Forged Steel Round Bar
Forged round bars are steel bars produced through open-die forging, a manufacturing process where heated steel billets are compressed between two flat dies to achieve the desired shape and dimensions. Unlike rolled or cast bars, forged bars undergo significant plastic deformation that refines the grain structure and eliminates internal defects.
The forging process ensures a minimum reduction ratio of 3:1, which guarantees superior material density, continuous grain flow, and exceptional mechanical properties including tensile strength, yield strength, and impact toughness. This makes forged round bars the preferred choice for critical applications in aerospace, oil & gas, power generation, and heavy machinery.
Technical Specifications
Size Range
Diameter Range
Standard: Ø150mm – 500mm
Heavy: Ø500mm – 1,000mm
Tolerance: ±1% of diameter or per spec
Length Range
Standard: 3m – 12m
Max: Up to 12,000mm
Max Weight: 25,000 kg per piece
| Diameter (mm) | Typical Length (m) | Max Weight (kg) |
|---|---|---|
| 150 – 300 | 3 – 12 | 5,000 |
| 300 – 500 | 3 – 10 | 10,000 |
| 500 – 700 | 2 – 8 | 15,000 |
| 700 – 1,000 | 2 – 6 | 25,000 |
Available Material Grades
| Category | ASTM / AISI Grades | EN / DIN Grades | Applications |
|---|---|---|---|
| Carbon Steel | AISI 1010, 1018, 1020, 1026, 1045, 1050 | C22, C35, C45, C55, S235JR, S355J2 | General engineering, shafts, pins |
| Alloy Steel | AISI 4130, 4140, 4150, 4340, 8620, 9310 | 42CrMo4, 34CrNiMo6, 34CrMo4, 20MnCr5 | Gears, axles, crankshafts, high-stress parts |
| Tool Steel | H13, D2 | 1.2344, 1.2379 | Dies, molds, mold bases |
Typical Mechanical Properties
| Grade | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) | Hardness (HB) |
|---|---|---|---|---|
| AISI 1020 / C22 | 410 – 540 | ≥ 250 | ≥ 25 | 120 – 160 |
| AISI 1045 / C45 | 620 – 780 | ≥ 370 | ≥ 16 | 180 – 230 |
| AISI 4140 / 42CrMo4 | 750 – 1,000 | ≥ 650 | ≥ 15 | 220 – 300 |
| AISI 4340 / 34CrNiMo6 | 930 – 1,080 | ≥ 830 | ≥ 12 | 280 – 340 |
| S355J2 / EN 10025 | 470 – 630 | ≥ 355 | ≥ 22 | 140 – 190 |
* Values are typical ranges; actual properties depend on heat treatment condition and bar size.
Surface Finish Options
As-Forged (Black)
Raw forged surface with mill scale. Most economical option suitable for further machining. Surface roughness Ra 12.5 – 25μm.
Rough Machined
Turned surface removing the outer layer. Provides dimensional control with surface roughness Ra 6.3 – 12.5μm.
Peeled
Centerless peeled for tight OD tolerance (±0.1mm). Ideal for shaft applications. Surface roughness Ra 3.2 – 6.3μm. Available for Ø 150 – 400 mm.
Polished / Ground
Precision ground or polished surface for critical applications. Surface roughness Ra 0.4 – 1.6μm. Mirror finish available on request.
Heat Treatment Services
| Treatment | Temperature Range | Purpose |
|---|---|---|
| Normalizing | 870°C – 925°C | Refine grain structure, uniform properties |
| Annealing | 790°C – 900°C | Improve machinability, relieve stress |
| Quench & Temper | 830°C – 870°C / 450°C – 650°C | Achieve high strength and toughness |
| Solution Treatment | 1,010°C – 1,120°C | Stainless steel corrosion resistance |
| Stress Relieving | 550°C – 650°C | Remove residual stresses after machining |
Quality Control & Testing
Non-Destructive Testing (NDT)
- Ultrasonic Testing (UT) – per ASTM E2375
- Magnetic Particle Testing (MT) – per ASTM E1444
- Liquid Penetrant Testing (PT) – per ASTM E165
- Dimensional Inspection – 100% record
- Surface Visual Inspection
Mechanical Testing
- Tensile Test – per ASTM E8
- Impact Test (Charpy V) – per ASTM E23
- Hardness Test (Brinell/Rockwell)
- Chemical Analysis – per ASTM E415
- Microstructure Examination
Certifications & Class Approvals
Quality Management
Mill Test Certificate
SGS / BV / Lloyd’s
Heat & Lot Tracking
Marine Classification Society Approvals
China Classification Society
Det Norske Veritas
American Bureau of Shipping
Nippon Kaiji Kyokai
Bureau Veritas
Lloyd’s Register
Registro Italiano Navale
Korean Register of Shipping
Manufacturing Process
Our forged steel products are produced through a 12-step forging process combining controlled heating, precision open/closed-die forging, tailored heat treatment, and CNC finish machining to achieve superior metallurgical structure and dimensional accuracy.
Raw Material Selection & Inspection
High-quality ingots or continuous-cast billets (EAF-LF-VD refined) are selected based on grade specification. Chemical analysis, surface inspection, and UT testing are performed.
Billet Sawing to Forging Blanks
Raw stock is cut to calculated forging weights using high-speed band saws, accounting for scale loss, flash, and machining allowances.
Furnace Heating
Blanks are heated to 1150–1250°C (depending on grade) in a gas-fired bogie-hearth or chamber furnace with precise zone temperature control to ensure uniform austenitization.
Open-Die / Closed-Die Forging
Heated blanks are forged using hydraulic presses or air hammers. Open-die forging uses flat/V-dies for simple bars; closed-die forging uses precision tooling for near-net-shape profiled components.
Trimming & Punching (Closed-Die)
For closed-die forgings, excess flash is trimmed in a mechanical press and holes are punched while the part is still hot, improving material utilization.
Post-Forging Heat Treatment
Forgings undergo normalizing, annealing, or quenching & tempering per material grade to refine grain structure, relieve residual stresses, and achieve specified hardness and mechanical properties.
Blasting & Surface Cleaning
Scale and oxide layer are removed by shot blasting (steel shot S230–S330) to reveal surface defects and prepare for machining.
Rough Machining
Excess forging allowance is removed by CNC lathe turning, leaving 2–3 mm finishing stock. Rough machining also removes surface decarburization and forging irregularities.
Ultrasonic Testing (UT)
100% ultrasonic inspection per EN 10228-3 or ASTM A388 detects internal defects such as cracks, inclusions, porosity, and segregation. Acceptance criteria as per grade requirements.
Finish Machining
CNC turning, milling, and drilling achieve final dimensional tolerances (up to IT7) and surface roughness (Ra 1.6–3.2 μm) per customer drawings.
Hardness & Metallographic Testing
Brinell/Rockwell hardness verification, tensile testing on sacrificial coupons, and metallographic examination for grain size, inclusion rating, and carbide structure (critical for tool/die steels).
Final Inspection & Packaging
Dimensional inspection of all critical features, MPI/LPT for surface defects if required, stamping grade and heat number, rust-proof oiling, and packing in wooden cases or steel bundles.
Applications
Where our products deliver proven performance across industries worldwide.
Shafts & Rotating Equipment
Forged round bar is the raw material for motor, pump, turbine, and marine shafts, where UT-verified internal soundness and through-hardened properties prevent in-service failures.
✓ UT per EN 10228-3
Gears, Pinions & Drive Components
Case-hardening and through-hardening grades (17CrNiMo6, 42CrMo4) supply gear blanks that carry high torque with controlled distortion.
✓ QT and case-hardening grades
Flanges & Pressure Fittings
Forged bar feeds flange rings, blind flanges, and fittings for pressure systems in carbon, alloy, and stainless grades.
✓ ASME/EN flange materials
Tooling & Die Holders
Pre-hardened and tool-steel rounds support die holders, mold bases, and tooling components requiring uniform hardness.
✓ Pre-hardened 2738/P20 options
Downhole & Wellhead Components
Alloy bar feeds wellhead blocks, valve bodies, and downhole tools requiring API-grade material with traceability.
✓ API 6A material classes
Custom Machined Components
Cut-to-length, pre-machined, and fully machined round bar components reduce your in-house machining cycle time.
✓ Cut-to-length + rough machining
Frequently Asked Questions
What is forged steel round bar?＋
Round bar produced by forging ingots or billets — rather than rolling — producing a refined, dense internal structure with no central porosity, specified for critical machined components.
What diameter range is available?＋
Typically Ø150 mm to 1,000 mm in forged-and-turned condition; lengths up to 12 m for smaller diameters. Other sizes on request.
What grades do you supply?＋
C45, 42CrMo4 / 4140, 34CrNiMo6 / 1.6582, 40CrNiMoA / 4340, S355J2 and selected tool steels (H13, D2) — others on request.
What heat treatment conditions are offered?＋
As-forged, normalized, normalized + tempered, quenched + tempered (through-hardened), and pre-hardened conditions with certified mechanical properties.
How is internal quality guaranteed?＋
100% ultrasonic testing per EN 10228-3/-4 with defined acceptance classes, plus grain size, inclusions, and mechanical testing per heat and lot.
What is the difference between forged and rolled bar?＋
Forging breaks down the cast structure more thoroughly, giving better toughness, fatigue strength, and isotropy — the reason critical shafts and gears start from forged bar.
What is the minimum order quantity and lead time?＋
Stock sizes from 1–5 tons; produced sizes typically 4–10 weeks depending on diameter and testing. Contact us for a firm quotation.
Can you supply machined or pre-machined bar?＋
Yes — peeled/turned, cut-to-length, with rough machining allowance, or fully machined to drawing.
What documentation comes with my order?＋
EN 10204 3.1 MTCs, UT test reports with acceptance class, heat treatment charts, and mechanical/chemical results; 3.2 certification on request.
How should I specify bar for a critical shaft?＋
Provide diameter, length, grade, heat treatment, mechanical property targets, UT acceptance class, and final application — we will propose the optimum supply condition.
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