Forged Flange Hubs
Forged steel flange hubs with a raised pilot boss, produced closed-die and finish-machined to suit the mating shaft.
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Forging Parts
Forged Bolt-Circle Flanges
Forged flanges with a dense bolt-hole circle, machined and faced for high-pressure bolted connections.
| 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
High-pressure and high-cycle flange joints depend on the bolt circle being exactly where the drawing says it is. These flanges are forged for strength, then the holes are drilled, faced and counterbored on the same machine, so the hole pattern and the sealing face are referenced to each other. Bolt holes can be spot-faced or counterbored to suit the specified fastener.
- Drilled, faced and counterbored on a single machine
- Bolt-circle position held to ±0.20 mm
- Spot-faced or counterbored holes to suit the fastener
- Forged material — mill certificate on request
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
- High-pressure pipe joints
- Pressure vessel nozzles
- Flange adapters
- Heavy machinery joints
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 |
| Bolt hole | Ø10 – Ø80 mm, position ±0.20 mm |
| Face finish | Ra 3.2 – 12.5 µm, per specification |
| Pressure class | To the specified rating, subject to material certification |
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 Ring Flanges
Forged ring flanges with a full-length sealing face, machined flat and parallel for a reliable gasket line.
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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.