Flange Nut and Bolt Selection | Hebei Wotu Fastener Manufacturing Co., Ltd.
A flange nut and flange bolt are selected as a joint, not as interchangeable fasteners. The integrated flange spreads clamping load over a wider area and can reduce the need for a separate washer, but the correct choice depends on the joint material, available clearance, thread system and service environment.
For a reliable enquiry, define whether you need a flange nut, a flange-head bolt or a matched assembly. The bearing surface, flange style, material, strength requirement and surface finish all affect fit and joint performance.
Brand: Wotu Surface: zinc plated Specifications: in stockM6/M8/M10/M12/M14/M16/M20 Chinese national standardfull range of specifications, support nonstandard thickness, tooth pitch customized Matching: can be matched with bolts of the same specification, flat washer, spring washer complete set of shipment Packaging: 25kg cartons, whole wooden pallets
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Brand: Wotu Surface: color zinc plated, blue-white zinc plated, black oxide, hot-dip galvanized, various surface treatments available Specifications: Comply with DIN934, GB/T6170, GB/T6172.1, GB/T6177.1 standards, in stock M6-M64 full range of specifications, support nonstandard customized Packaging: woven bag inside/25kg export carton, full-container wooden pallet wrapped with film, supports private-label, neutral export packaging
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Brand: Wotu Surface: overall hot-dip zinc plating treatment Specifications: Comply with DIN and GB standards, in stock M6-M48 full range of specifications, length 20mm-300mm, supports nonstandard customized. Packaging: woven bag inside / 25kg export carton, film-wrapped wooden pallet; supports neutral packaging and customer private-label customization.
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Brand: Wotu Surface: quenching and tempering heat treatment + high temperature black oxide anti-rust treatment Specifications: Comply with DIN934, GB/T6170 standards, in stock M6-M48 full range of specifications, nonstandard sizes can be customized Packaging: 25kg carton/woven bag inner packaging, whole wooden pallet wrapped with film for export packaging, supports neutral/private-label customization packaging
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Brand: Wotu Surface: natural black oxide / hot-dip galvanized / blue-white zinc plated, multiple processes available Specifications: Based on common industry drawing parameters, suitable for pipe diameter 25mm~139.7mm, screw diameter M10~M24, total length can be nonstandard customized Matching: can be matched with nut, flat washer and spring washer of the same specifications for complete shipment Packaging: Bundling and packaging + 25kg export carton, full-container wooden pallet wrapped with film, supports private-label export packaging
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Brand: Wotu Surface: Natural black oxide treatment, customized hot-dip galvanized, zinc plated as required Specifications: Follow Chinese national standard GB/T799-1988, in stock M12-M48, total length 120mm~1500mm, nonstandard customized diameter, bending length, total screw length available Matching: Nuts, flat washers and spring washers of the same specification can be supplied in complete sets. Packaging: Bundling and packaging, using wooden pallets and film-wrapped export packaging in large quantities
Read MoreFlange fastener selection
Compare flange nuts and flange bolts by thread compatibility, flange diameter, plain or serrated bearing surface, material, strength class, finish and dimensional tolerance. The right selection should also account for the mating material, installation access, reuse expectations and exposure to corrosion or vibration.
| Criterion | What To Check | Why It Matters | Buyer Tip |
|---|---|---|---|
| Thread size and pitch match between the bolt and flange nut | Confirm the bolt diameter, thread pitch, and thread standard on both parts before ordering them as a set. | A flange nut that starts but does not fully run down the bolt can gall, strip, or give a false sense of clamp load. | Ask: “Can you confirm the exact thread standard and pitch for both the flange nut and the matching bolt?” |
| Flange face style and bearing surface | Identify whether the nut needs a smooth flange face or a serrated flange face, and check the mating material surface. | A smooth flange spreads load without biting into the surface, while a serrated flange can resist loosening but may mark coatings or softer materials. | Ask: “Is the flange nut serrated or non-serrated, and is it suitable for the surface finish on our assembly?” |
| Bolt length and usable thread engagement | Compare grip thickness, washer use, nut height, and the amount of bolt thread available after tightening. | Too little engagement weakens the joint; too much extra thread can interfere with nearby parts or increase assembly time. | Ask: “Given our clamped thickness, what bolt length leaves proper thread engagement with this flange nut?” |
| Strength grade and material compatibility | Match the bolt grade and nut grade, and confirm the base material and heat treatment requirements if the joint carries load. | A high-strength bolt paired with an unsuitable nut can fail at the threads before the joint reaches the intended clamp force. | Ask: “Which bolt grade and flange nut grade are intended to be used together for this assembly?” |
| Coating, plating, and friction behavior | Confirm the surface finish on both parts and whether tightening torque guidance changes with that finish. | Zinc plating, black oxide, hot-dip galvanizing, and other finishes can change corrosion resistance, thread fit, and clamp load at a given torque. | Ask: “What finish is supplied on the bolt and flange nut, and should our tightening torque be adjusted for it?” |
A flange nut usually provides the wider bearing surface on the nut side of a joint, while a flange bolt combines a bolt head with an integral flange on the opposite side. A complete flange bolt and nut assembly may be useful when both sides of the joint need controlled load distribution.
Choose a serrated flange only when its locking action and surface contact suit the application. Serrations can mark painted, plated or softer materials, so a plain flange may be the better option where surface damage or easy removal matters.
Start with the joint drawing or a clear sample. Confirm the thread diameter, pitch and thread standard, along with the required bolt length and the thickness of every clamped part. A flange nut with the wrong thread can appear to fit briefly but will not produce a dependable assembly.
Match the bearing surface to the joint. A wider flange can distribute load across a larger area, while a serrated flange may resist turning but can damage coatings or leave marks. Check clearance around the bolt head and nut before choosing the flange diameter and profile.
Specify material, strength class and finish according to the load and environment. Outdoor exposure, moisture, heat, corrosion, vibration and contact with dissimilar metals can change the suitable combination. Do not assume that a standard-looking bolt and nut have compatible strength or corrosion characteristics.
Before requesting a quotation, send the application, drawing or photo, thread information and the required material or finish. Ask Hebei Wotu Fastener Manufacturing Co., Ltd. whether the requested flange nut, flange bolt or matched set is available in the required configuration, and confirm inspection or documentation requirements before placing an order.
| Criteria | Importance | Description | Example Options |
|---|---|---|---|
| Plain flange versus serrated flange | Important when surface condition, vibration resistance and future removal all matter. | A plain flange provides a smooth bearing surface. Serrations may resist rotation but can mark coatings or softer mating materials. | Use a plain flange for a finished painted panel; consider a serrated flange only where its surface-gripping action suits the joint. |
| Integrated flange versus separate washer | Important for load distribution, clearance and the condition of the mating surface. | An integrated flange combines the bearing feature with the nut or bolt head, while a separate washer allows the washer material and size to be selected independently. | A compact frame may favor an integrated flange, while a sensitive surface may require a separately selected washer. |
| Thread compatibility | Essential for correct assembly and dependable clamping. | The bolt and nut must share the correct nominal diameter, pitch and thread standard; matching diameter alone is not sufficient. | Confirm the specified thread system and pitch before pairing a flange nut with a flange-head bolt. |
| Material, strength class and finish | Important for load, corrosion exposure, temperature and contact with the mating parts. | The selected combination should suit the joint load and environment. Different materials or finishes can create compatibility or corrosion concerns. | An outdoor joint may need a different material or finish review than an indoor equipment frame. |
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It suits joints where a wider integrated bearing surface can distribute clamping load or reduce the need for a separate washer. Check the joint material, available clearance, installation access and load before selecting the flange diameter and fastener configuration.
A serrated flange can resist turning by biting into the mating surface, which may help in some vibration-prone assemblies. A plain flange is often preferable when the surface must remain undamaged, the fastener will be removed and reused, or the joint uses painted, plated or softer material.
No. The flange provides an integral bearing surface, but it does not automatically suit every joint or replace every washer function. Review the bearing area, surface hardness, coating, clearance and installation requirements before omitting a separate washer.
No. The thread pitch and thread standard must match, and the material, strength class and finish should be compatible with the joint and service environment. A fastener that shares the nominal diameter but has a different thread can fit poorly or fail to clamp correctly.
Provide the application or drawing, thread diameter and pitch, thread standard, bolt length, clamped material thickness, flange style and required material, strength class or finish. A clear photo or sample can also help clarify the required configuration; ask whether the requested flange nut, flange-head bolt or matched set can be supplied with the documentation you need.
Please provide the application or drawing, thread size and standard, and the required material, strength class or surface finish so the requested flange fastener configuration can be reviewed.
