Short answer: Stamped sealing flanges need RFQ details that connect flatness to the gasket, fasteners, and final assembly. Define sealing face, gasket type, hole pattern, burr direction, surface finish, coating thickness, free-state versus clamped flatness, inspection fixture, leakage test if any, and packaging rules that prevent warped or scratched sealing faces.
Stamped flanges, covers, retainers, clamps, and enclosure plates may need to seal against foam, rubber, adhesive, liquid gasket, EMI material, or a machined mating face. A part can meet outline dimensions and still leak if the sealing face is warped, scratched, burred, or uneven after coating.
Use this page with the flatness and warpage control guide, surface finish inspection guide, የብረት ሉህ enclosure DFM guide, and packaging guide.
Sealing flange RFQ decisions
| Decision | Why it matters | RFQ detail |
|---|---|---|
| Sealing face | The controlled surface may not be the visually obvious surface. | Marked face, no-scratch zones, and inspection lighting. |
| Flatness condition | Free-state flatness and clamped sealing can give different results. | Free-state, restrained, or assembled inspection method. |
| Burr direction | A burr toward the gasket can cut foam, rubber, or coating. | Burr side, edge break, and gasket contact rule. |
| Coating and finish | Thickness buildup or rack marks can create leak paths. | Final coating, masked zones, thickness range, and sample standard. |
Tie flatness to the gasket system
A sealing flange should not be quoted from a flatness number alone. Foam tape, molded rubber, adhesive bead, EMI gasket, and liquid sealant all tolerate different surface conditions. Fastener spacing, clamp load, mating face stiffness, and hole position also decide whether the seal is reliable.
Tell the አቅራቢ whether the part must be flat on a table, flat in a check fixture, or sealed after screws are tightened. For thin parts, free-state flatness can look poor while the assembly seals well. For rigid mating faces, a small high spot or burr can create a leak. This is why inspection should connect to function, similar to the functional gage guide.
Control burrs, scratches, and coating buildup
The sealing surface should be identified on the drawing. Burrs, rolled edges, handling scratches, weld spatter, coating chips, powder buildup, and rack marks may matter more than general cosmetic appearance. If the gasket contacts a sheared edge, define edge break and burr direction before tooling.
If the part is plated, powder coated, painted, or made from pre-coated sheet, decide whether coating thickness is included in the flatness or stack height. Review route options with the pre-coated steel guide, powder coating masking guide, and burr control guide.
For adhesive-backed gaskets, also control oil residue and fingerprints because a dimensionally good flange can still fail bond or compression checks.
RFQ details to include
- Drawing and model with sealing face, gasket type, mating face, fastener pattern, datum scheme, and no-scratch zones.
- Material, thickness, temper, formed features, bend direction, burr side, and edge break requirement.
- Flatness requirement in free-state, restrained fixture, or assembled condition, plus measurement method.
- Surface finish, coating thickness, masked areas, corrosion requirement, and acceptable rack marks or witness marks.
- Leak, water spray, compression, visual, or functional fit tests if required for first articles.
- Packaging method that prevents stacked parts from bending, rubbing, or damaging the sealing face.
How to approve sealing samples
Check the sample with the real gasket or a representative substitute. Measure hole pattern, inspect the sealing face under useful light, confirm burr direction, and look for coating buildup around holes, corners, and edges. If the assembly is clamped, test the part in the clamped condition, not only loose on a granite plate.
A አቅራቢ should explain how flatness will be protected through stamping, deburring, finishing, and packaging. Thin flanges can be bent after they leave the press, so packing is part of quality control, not just shipping.
Send drawings, gasket information, finish, flatness condition, and test need through the contact page. If the sealing system is still being designed, use the RFQ form to ask for DFM comments on edge condition, hole spacing, and inspection method before tooling.
FAQ
Why do stamped sealing flanges leak?
Common causes include poor flatness, burrs toward the gasket, scratches, hole pattern error, uneven coating, weak clamp load, or packaging damage.
Should flange flatness be measured free-state or clamped?
Use the condition that matches function. Some flanges need free-state flatness, while others should be checked in a fixture or assembled condition.
Does coating affect gasket sealing?
Yes. Powder, paint, plating, chips, rack marks, or thickness buildup can change surface condition, stack height, and sealing pressure.
What should be sent for a sealing flange RFQ?
Send drawings, gasket type, sealing face, material, thickness, flatness condition, burr side, finish, test requirement, packaging rule, and volume.