Forged Rings & Hollow Forgings
Seamless forged rings, sleeves and hollow cylinders with sound, void-free walls — for pressure, energy and heavy mechanical applications.
Forged Rings & Hollow Forgings
Forged rings and hollow cylinders are punched, expanded and bored from solid forgings, producing a seamless, fibrous wall with no weld seam and uniformly refined grain. The process suits pressure-retaining parts, rotating sleeves and heavy tooling where cast or rolled alternatives fall short.
Reference delivery: a Ø1,600 × Ø920 mm sleeve weighing 14.4 tonnes, produced by our Shandong partner mill (Panjin) on a 50 MN hydraulic press with EBT+LF+VD/VOD melting and electroslag remelting available for critical grades. Products include ring forgings, tube and sleeve forgings, forged mandrels (H13) and precision forged tube blanks.
Technical Specifications
Available Material Grades
| Category | Typical Grades | Typical Applications |
|---|---|---|
| Alloy Steel | 42CrMo4 / 4140, 35CrMo, 40Cr | Mechanical sleeves, flanges stock, tooling |
| Pressure-Vessel Steel | 15CrMo, 12Cr1MoV, SA-106C equivalents | Boiler and pressure-part hollows |
| Hot-Work Steel | H13 / 1.2344 | Extrusion mandrels, core barrels |
| High-Temperature Steel | F91 / F92 equivalents, 25Cr2Ni3MoV | Power-generation rings and sleeves |
* Other grades available on request against chemical composition or drawing.
Available Dimensions
| Product Type | Size Range | Max Piece Weight |
|---|---|---|
| Ring Forgings | OD ≤ Ø2,400 mm × Height ≥ 100 mm | ~15 t |
| Tube / Sleeve Forgings | OD Ø400 – 2,400 mm × Length 1,500 – 4,000 mm | ~15 t |
| Disc Forgings | Ø300 – 2,500 mm × Height ≥ 100 mm | ~15 t |
* Typical ranges; special geometries per drawing on request.
Typical Applications
Pressure & Boiler Parts
Seamless hollows for pressure vessels, boiler cylinders and nozzle stocks, with impact-tested certificates.
Extrusion & Piercing Tooling
H13 mandrels and core barrels for seamless tube mills, ESR-melted for internal cleanliness.
Machine Barrels & Sleeves
Bored and machined barrels for hydraulic cylinders, extruders and rolling equipment.
Energy & Nuclear Components
Large sleeves and rings for wind, conventional and nuclear power equipment, with full traceability.
Quality Control & Testing
Non-Destructive Testing (NDT)
- Ultrasonic Testing (UT) – per EN 10228-3 / ASTM A388
- Magnetic Particle Testing (MT) – per ASTM E1444
- Liquid Penetrant Testing (PT) – per ASTM E165
- Dimensional Inspection – 100% recorded
Mechanical Testing
- Tensile Test – per ASTM E8 / EN ISO 6892
- Impact Test (Charpy V) – per ASTM E23
- Hardness Test (Brinell / Rockwell)
- Chemical Analysis – spectrometric
Certification: EN 10204 3.1 mill certificate standard, 3.2 via third-party inspection (SGS / BV / TUV) on request. Heat number stamped on every piece for full traceability.
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 hollow forgings do you supply?＋
Seamless ring forgings up to Ø2400 mm, tube and sleeve forgings Ø400–2400 mm, forged H13 mandrels and precision forged tube blanks.
Why choose a forged ring over a rolled or welded one?＋
Forging produces a seamless, fibrous wall with no weld seam and uniformly refined grain — critical for pressure retention and rotating duty.
What is the maximum piece weight?＋
Approximately 15 tonnes per piece; reference delivery: a Ø1,600 × Ø920 mm sleeve weighing 14.4 t.
What grades are available?＋
42CrMo4 / 4140, 35CrMo, 15CrMo, 12Cr1MoV, H13 / 1.2344 and high-temperature grades — others on request.
Can IDs and ODs be machined?＋
Yes — bored and turned to drawing with specified tolerances and surface finish.
How is quality verified?＋
100% ultrasonic testing per EN 10228-3 / ASTM A388, plus mechanical testing per heat; EN 10204 3.1 certification standard, 3.2 on request.
Ready to Source Forged Rings & Hollows?
Tell us the OD, ID and length you need. Our engineering team responds within 24 hours.
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