Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Incoloy 800H Wing Nuts
Incoloy 800H wing nuts are hand-tightened nuts with two opposed projecting wings that allow finger-only torque application, machined from ASTM B408 round bar or forged from ASTM B564 blanks for applications where frequent removal without tools is required and the corrosion-resistance of the Incoloy 800H alloy is required for the service environment. TorqBolt manufactures wing nuts in two variants: DIN 315 (American form, rounded wings) and DIN 7993 (rectangular wings). Standard diameter range is M6 to M24 with hand-tightening torque limited to approximately 5 to 50 Nm depending on diameter. Internal threads are tapped to class 6H per ISO 965 (metric) or class 2B per ASME B1.1 (inch). Wing nuts are NOT recommended for sustained high-temperature service above 540 deg C; their applications are inspection-cover bolting, instrument-enclosure bolting, filter-housing bolting and access-panel fastening where hand-tightening and frequent removal without specialist tools is required. Every wing nut ships with EN 10204 type 3.1 mill test certificate documenting heat number, ASTM B408 chemistry, solution-anneal cycle (1149 deg C plateau followed by rapid quench) and ASTM grain size 5 verification on the body and wing transition area.
Wing Nut Dimensions (DIN 315 / DIN 7993)
| Size designation | Across flats / OD | Head / nut height | Thread pitch | Standard reference |
|---|---|---|---|---|
| M6 | 6.0 mm thread | Wing span 25 mm; Body height 9 mm | 1.0 mm | DIN 315 |
| M8 | 8.0 mm thread | Wing span 32 mm; Body height 11 mm | 1.25 mm | DIN 315 |
| M10 | 10.0 mm thread | Wing span 38 mm; Body height 13 mm | 1.5 mm | DIN 315 |
| M12 | 12.0 mm thread | Wing span 45 mm; Body height 16 mm | 1.75 mm | DIN 315 |
| M16 | 16.0 mm thread | Wing span 55 mm; Body height 19 mm | 2.0 mm | DIN 315 |
| M20 | 20.0 mm thread | Wing span 65 mm; Body height 23 mm | 2.5 mm | DIN 315 |
| M24 | 24.0 mm thread | Wing span 75 mm; Body height 27 mm | 3.0 mm | DIN 315 |
Manufacturing Route at TorqBolt
Wing nut manufacture is either CNC milled from bar (DIN 7993 rectangular wings) or forged from blank (DIN 315 rounded wings) followed by thread tapping:
- Receive Incoloy 800H bar to ASTM B408 or forged blank to ASTM B564; PMI verification.
- Cut bar to nut-blank size, or visually inspect forged blank for surface defects.
- CNC mill the wing-and-body profile per DIN 315 (rounded) or DIN 7993 (rectangular).
- Drill the through-hole; tap the internal thread to class 6H per ISO 965.
- Solution anneal at 1149 deg C plateau followed by rapid quench; ASTM grain size 5 verified.
- Hardness band 120-184 HB on first piece and one per batch.
- Visual + dimensional + PMI inspection 100 percent.
- Verify wing-to-body transition for surface defects (high-stress area on hand-tightening).
- VCI wrap, pack with matched bolts or studs on PO call-out; CoC + EN 10204 cert.
Wing Nut Sizes Stocked and Lead Times
| Diameter range | Length range | Stock status | Lead time |
|---|---|---|---|
| M6 - M10 | Per DIN 315 | Made-to-order from stock bar | 10 to 14 working days |
| M12 - M16 | Per DIN 315 | Made-to-order from stock bar | 14 to 18 working days |
| M20 - M24 | Per DIN 315 | Made-to-order, forged blank | 3 to 5 weeks |
Inspection and Heat Marking
Wing nut specific inspections cover wing-to-body transition (high-stress area on hand-tightening), thread tap quality and surface finish:
- Wing-to-body transition visual inspection for surface defects and machining marks.
- Internal thread verified with class 6H plug gauge.
- Wing span and body height verified per DIN 315 schedule.
- Hardness band 120-184 HB on first piece and one per batch.
- ASTM E112 grain-size etch verification.
- PMI by X-ray fluorescence on first piece and one per batch.
- Surface finish verified on wing surfaces (hand-contact area).
- Heat number traceable to bar.
Typical Service Conditions
Wing nuts are specified for hand-tightened access-panel bolting and frequent-removal applications:
- Inspection-cover bolting on pressure-vessel external instrument enclosures.
- Filter-housing access-cover bolting on process-stream filter assemblies.
- Calibration-port access on heat exchanger external instrument fittings.
- Furnace component instrumentation-port bolting at ambient locations.
- Sampling-port closure on process-line bypass instrument fittings.
- Ambient-temperature access-panel fastening where Incoloy 800H is required for corrosion resistance.
Incoloy 800H Alloy Considerations on This Fastener Form
Companion Fasteners and Related Pages
- Hex Nuts: tool-tightened standard nut alternative for permanent fastening.
- Coupling Nuts: extended-hex alternative for threaded-rod joining.
- Lock Nuts: prevailing-torque alternative for vibration-resistance.
- Eye Bolts: hand-installed lifting fastener variant.
- Washers: spacer washers under wing nuts.
Frequently Asked Questions
Q. Are wing nuts suitable for high-temperature service?
No. Hand-tightening provides limited preload, insufficient for high-temperature flange bolting where thermal expansion would loosen the joint. Wing nut applications are restricted to access-panel and instrument-cover bolting where hand-tightening is acceptable and frequent removal is required.
Q. What is the difference between DIN 315 and DIN 7993?
DIN 315 has rounded wings (American form, also called butterfly nut). DIN 7993 has rectangular wings (European form). Both use the same body geometry; the wing-shape difference is cosmetic and ergonomic.
Q. What is the maximum tightening torque for a wing nut?
Hand-tightening produces approximately 5 to 50 Nm depending on diameter. Tool-tightening with pliers is not recommended; wing nuts are designed for hand-only torque application.
Q. Can wing nuts be supplied in inch sizes?
Yes. ASME B18.6.9 wing nuts 1/4 inch through 1 inch are machined on PO call-out from B408 bar with class 2B UNC threads.
Q. Are wing nuts forged or machined?
Both variants are supplied. DIN 315 rounded wings are typically forged from ASTM B564 blanks. DIN 7993 rectangular wings are typically CNC milled from ASTM B408 bar.
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