What This Part Is And Why It Is Made This Way
Flanges and sleeves are connection parts, so their value is in the interface: bolt circle position, face flatness and bore fit. A part that is strong but out of position is still scrap.
These components are cast or forged in steel grades and then machined on the sealing face, the bore and the bolt pattern.
What You Get From This Route
Bore and face machined to the assembly requirement rather than left as cast.
Forged or cast route selected by batch size instead of by what the supplier prefers.
Dimensional inspection of the bolt circle before shipment.
Application Scenarios
- Pipework and pressure equipment connections
- Gearbox and housing interfaces
- Hydraulic cylinder end connections
- Structural sleeve joints in machinery frames
Who It Is For
- Equipment builders standardising connection parts across machine models
- Buyers replacing imported flanges with a qualified alternative
- Maintenance teams needing dimensionally interchangeable spares
Technical Features
- Cast or forged steel construction
- Machined sealing face, bore and bolt pattern
- Steel grades to customer drawing
- Dimensional inspection before delivery
What Buyers Run Into Without This Specification
- Face flatness is out of tolerance and the joint leaks under pressure.
- The bolt circle is rotated relative to the drawing and parts will not mate.
- Raw castings arrive and the buyer has to find a machine shop separately.
Published Material Weight And Process Data
Figures below are the published capability for steel castings and forgings. Part specific values — tolerance on individual features, finish, packing — are confirmed at drawing review and marked TBC until then.
| Material | 42CrMo4, G20Mn5, G26CrMo4, G18NiMoCr3-6, G22CrNi2Mo5-6, AISI 4340, AISI 4140, AISI 4325 and similar grades |
|---|---|
| Weight Range | Steel casting 50 kg - 20 T; forging 50 kg - 50 T |
| Process | Sand casting; shell moulding; open-die and closed-die forging; roll forging |
| Melting | High automation production lines with EAF + LF + VD / AOD melting routes |
| Tolerance | Zero draft sand casting to CT9 on automated heat treatment lines |
| Inspection | NDT with certified operators, single part certificates and quality document traceability |
| Part Specific Tolerance | TBC — confirmed against the customer drawing |
| Minimum Order Quantity | TBC — depends on the process route selected |
| Lead Time | TBC — confirmed with the production base at quotation |
How The Part Is Made And Checked
- Production — Highly automated production lines with EAF + LF + VD / AOD melting equipment.
- Quality — Certified NDT capability, supporting per-part certificates and traceable quality documents.
- Process Control — Automated heat treatment lines; zero draft sand casting reaches CT9.
Quality management is based on ISO 9001 and covers supplier management, raw material inspection, production process control and final inspection. Inspection results are archived and traceable.
Options And Alternatives
Parts are produced to the customer drawing rather than to a fixed catalogue item, so material grade, machining scope, surface treatment and packing are all specified per order. Machining, dimensional control, surface treatment and necessary pre-assembly can be added to the same supply route.
Where another process family would suit the part better — for example a forging in place of a casting for a shock loaded connector — that comparison is raised during drawing review rather than after tooling is committed.
How To Specify This Part
Mark which face is the datum on the drawing. On flange and sleeve parts the datum choice changes the whole machining plan, and an unclear datum is the single most common reason a first article fails the gauge.
- Send the drawing with material, quantity, quality standard and target delivery date.
- State the inspection class and the zones it applies to, rather than a general note.
- Confirm the packing requirement and the lifting equipment available at the destination.
Related Guides
Other Parts In This Range
Large Steel Structural Castings
Load bearing steel castings up to 20 tonnes
View specifications
Slewing Support Structural Castings
Rotating support bodies with machined bearing seats
View specifications
Forged Shafts
Stepped shafts with continuous grain flow
View specifications
Large Gear Rings
Cast and forged ring gears for heavy drives
View specificationsFlanges and Sleeve Components — Frequently Asked Questions
Do you supply flanges to a standard or only to drawing?
Parts are produced to the customer drawing. If a standard is referenced on the drawing it is applied, but the drawing dimensions govern acceptance.
Can flanges and sleeves be supplied fully machined?
Yes. CNC machining, dimensional control and surface treatment are coordinated in the same supply chain.
What do you need to prepare a quotation?
Drawings, material, quantity, quality standard and target delivery date.
Which inspection is included?
The inspection scope is agreed during drawing review. Automated heat treatment lines; zero draft sand casting reaches CT9.
Get A Quotation For Flanges and Sleeve Components
Send the drawing and the application. We will confirm the process route, the production base and the inspection scope before quoting.