Forged Ring Flanges
Forged ring flanges with a full-length sealing face, machined flat and parallel for a reliable gasket line.
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Forging Parts
Forged Flange Hubs
Forged steel flange hubs with a raised pilot boss, produced closed-die and finish-machined to suit the mating shaft.
| Forging weight | 0.5 – 25 kg per part, per die set |
|---|---|
| Tolerance | ±1.5 mm as-forged; finished to ±0.05 mm after machining |
| Heat treatment | Quench and temper, normalising or annealing — to specification |
About this part
What it is and why it is made that way
A flange hub is the joint between a rotating shaft and the pipe or vessel it drives. Forging gives the material the grain flow and density a welded or machined-from-plate flange cannot match, and the closed-die profile keeps the bolt circle concentric. The pilot boss is then machined to the shaft diameter, so the fit is a matter of the tolerance you specify.
- Closed-die forging with controlled grain flow
- Pilot boss machined to the specified shaft fit
- Bolts drilled and faced on the flange face
- Balanced on request for rotating applications
Materials
- C45 / 40Cr carbon steel
- 42CrMo alloy steel
- 20CrMnTi / 20CrMnMo gear steel
- Stainless 304 / 17-4PH
- Alloy steel 40CrNiMoA
Production processes
- Open-die forging
- Closed-die forging
- Hot and cold forging
- Heat treatment
- CNC finish machining
Typical applications
- Pump and pump-set flanges
- Shaft couplings
- Pipe and vessel connection
- Agitator drive hubs
Specification
Technical detail
The ranges below are what this shop typically holds. Anything tighter than the baseline is possible — send the drawing and we will confirm it against your specific tolerances rather than quote from a table.
| Forging weight | 0.5 – 25 kg per part, per die set |
|---|---|
| Tolerance | ±1.5 mm as-forged; finished to ±0.05 mm after machining |
| Heat treatment | Quench and temper, normalising or annealing — to specification |
| Material certification | Mill test certificate available on request |
| Forging ratio | Up to 4:1, per die set |
| Flange diameter | Ø80 – Ø500 mm |
| Bolt circle | Per drawing, holes drilled to ±0.20 mm position |
| Runout | ≤0.05 mm TIR on the machined pilot, when balanced |
Material and finish are yours to choose. The lists above are the families this part is normally made in. We will not substitute a grade or change a tolerance without telling you first — and asking.
In the same process line
Other Forging parts
If this is not quite your part, these are made on the same equipment with the same inspection.
Forged Bolt-Circle Flanges
Forged flanges with a dense bolt-hole circle, machined and faced for high-pressure bolted connections.
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Forged Sprockets & Gear Rings
Forged steel sprockets and toothed rings, cut and heat-treated for chain drives and indexing systems.
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Get a quote for this part
Send the drawing and we will quote it against your material, your tolerance and your quantity. One business day, in writing, with a lead time you can plan around.