High Crown Acorn Nuts (Inch Series)
High crown acorn nuts, inch series #4–1 nominal — the two-piece closed-end dome-top hex cap nut with the full-height crown, with the collected per-size table: width across flats and corners, basic major diameter and overall height range.
Last updated: 2026-11
Specifications
The high crown acorn nut is the full-dome member of the cap-nut family: a two-piece closed-end hex cap nut, assembled from the hex body and the dome crown, that completely encloses the thread run-out above the nut. Against the low crown pattern (covered on its own page) it stands taller for the same wrench size — the tabulated data shows 0.572 in overall height at 1/2 nominal where the low crown stands 0.81 in overall but on a taller hex — and it is the pattern chosen where the envelope allows the full dome and the closed top matters: decorative hardware, exposed assemblies, and protection of thread ends from corrosion, snagging or tampering. Two-piece construction means the crown is a separate dome swaged onto the hex, which is the form the table describes. The table runs #4 through 1 nominal (0.112–1.000 in basic major diameter), fifteen sizes, and carries per size: basic major diameter, width across flats F (max/min — 0.3125/0.302 from #5 through #8, growing to 1.497/1.447 at 1), across corners G (max/min — blank at #4 and 3/4, see table notes) and overall height H (max/min). No governing standard is named for the pattern and hexagon height, drill depth and full thread are not tabulated — quote the size and thread and those are confirmed at RFQ. Threads, property classes and finishes are not tabulated — per RFQ.
| Pattern | High crown acorn (dome-top) hex cap nut, two-piece closed-end construction — full-height dome fully encloses the thread run-out; the "high crown (deep)" designation is the catalog's standard-context note for the pattern the published table titles "Two Piece Closed-End Hex Cap Nuts" |
|---|---|
| Size range | Nominal #4 – 1 in (basic major dia. 0.112 – 1.000), fifteen sizes in the tabulated ladder |
| Tabulated geometry | Per size: basic major dia., width across flats F (max/min), across corners G (max/min), overall height H (max/min) — e.g. 1/2: F 0.750/0.736, G 0.866/0.840, H 0.572/0.552 |
| Gaps in the tabulated data | G (corners) cells are blank at #4 and 3/4; H at 7/16 and 9/16 breaks the surrounding height progression (0.680 and 0.482 between 0.432 at 3/8 and 0.572 at 1/2) — reproduced verbatim and flagged in the table notes; verify before quoting those sizes |
| Threads / classes / finishes | Not tabulated by the collected specification — per RFQ (state thread series and finish at quotation) |
| Nominal Size or Basic Major Dia. of Thread | Basic Major Dia (in) | Width Across Flats (F) Max | (F) Min | Width Across Corners (G) Max | (G) Min | Overall Height (H) Max | (H) Min |
|---|---|---|---|---|---|---|---|
| #4 | 0.1120 | 0.248 | 0.225 | - | - | 0.200 | 0.177 |
| #5 | 0.1250 | 0.3125 | 0.302 | 0.361 | 0.344 | 0.260 | 0.240 |
| #6 | 0.1380 | 0.3125 | 0.302 | 0.361 | 0.344 | 0.260 | 0.240 |
| #8 | 0.1640 | 0.3125 | 0.302 | 0.361 | 0.344 | 0.291 | 0.271 |
| #10 | 0.1900 | 0.3750 | 0.362 | 0.433 | 0.413 | 0.291 | 0.271 |
| 1/4 | 0.2500 | 0.4375 | 0.423 | 0.505 | 0.482 | 0.338 | 0.318 |
| 5/16 | 0.3125 | 0.562 | 0.545 | 0.650 | 0.621 | 0.385 | 0.365 |
| 3/8 | 0.3750 | 0.625 | 0.607 | 0.722 | 0.692 | 0.432 | 0.412 |
| 7/16 | 0.4375 | 0.673 | 0.659 | 0.775 | 0.750 | 0.680 | 0.660 |
| 1/2 | 0.5000 | 0.750 | 0.736 | 0.866 | 0.840 | 0.572 | 0.552 |
| 9/16 | 0.5625 | 0.875 | 0.861 | 1.010 | 0.982 | 0.482 | 0.462 |
| 5/8 | 0.6250 | 0.938 | 0.909 | 1.083 | 1.037 | 0.807 | 0.787 |
| 3/4 | 0.7500 | 1.12 | 1.08 | - | - | 1.12 | 1.08 |
| 7/8 | 0.8750 | 1.250 | 1.212 | 1.443 | 1.382 | 1.420 | 1.380 |
| 1 | 1.0000 | 1.497 | 1.447 | 1.728 | 1.650 | 1.572 | 1.414 |
- Row 1 (#4): The #4 row's G (across corners) cells are blank ("-") — reproduced verbatim; across-corners geometry for #4 is not established in the tabulated data.
- Row 9 (7/16): The overall-height pair at 7/16 (0.680/0.660) sits above both neighbours (3/8 = 0.432/0.412, 1/2 = 0.572/0.552), breaking the height progression — transcribed verbatim from the page; probable source typo, do not normalize. Verify before quoting 7/16.
- Row 11 (9/16): The overall-height pair at 9/16 (0.482/0.462) sits below the 1/2 row (0.572/0.552) — transcribed verbatim; probable source typo, do not normalize. Verify before quoting 9/16.
- Row 13 (3/4): The 3/4 row's G (across corners) cells are blank ("-"), and its F and H values print two decimals against the surrounding three-decimal pattern — reproduced verbatim. Verify before quoting 3/4.
- Row 7 (5/16): F/G at 5/16 and 3/8 and the 7/16 row print mixed decimal widths in the source (0.562 vs 0.3125) — page layout preserved verbatim, values unchanged.
Materials
- Material and finish specified per RFQ — high crown acorn nuts are often chosen for exposed or decorative assemblies; state the exposed-surface finish requirement with the order
Ordering & documentation
Documents
Shipments are backed by Mill Test Certificate (MTC), Dimensional Report, Salt Spray Test Report on request, with full batch traceability from raw material to finished product. Quality management follows the owner-confirmed compliance list: ISO 9001:2015, RoHS, REACH. Exact document sets are confirmed on the order.
Quotation
- The fastener family (High Crown Acorn Nuts (Inch Series)) plus the standard designation from your drawing — DIN / ISO / JIS / ASTM / ANSI, or a drawing for custom parts.
- Size (diameter and length), thread type (metric or inch), property class or grade, and coating or finish.
- Quantity per size and your target delivery date.
- Destination country, and any required documents (for example a mill test certificate) so the quote includes them.
Sample & supply
Minimum order quantity is 10,000 pieces. Stock items run 3–7 days. Quantities or variants outside the standard range are confirmed at quotation.
Storage & shipping
Parts are packed for export and shipped factory-direct to buyers in Europe, Asia, the Americas and the Middle East. Store fasteners dry and protected until installation, and keep coated parts in their packaging until use; specific packing and preservation requirements can be stated on the order and confirmed at quotation.
Frequently asked questions
High crown or low crown acorn nut — how do I choose?
Both patterns close the thread run-out under a dome; the difference is how much envelope the dome occupies and how the nut is made. The collected tables let you compare per size: at 1/2 nominal the high crown (two-piece) stands 0.572–0.552 in overall with a 0.750–0.736 flat, and the low crown (one-piece) page carries its own H/Q columns for the same size. Two-piece construction means the crown is a separate dome assembled onto the hex body — the traditional full-dome cap nut — while the low crown pattern is machined or cold-formed in one piece with the dome shortened for clearance. Choose high crown where the full dome fits and a finished, fully enclosed appearance or maximum thread-end protection is the point; choose low crown where the dome must clear a cover, channel or moving part. Before quoting, check the table notes on this page: the source table leaves the across-corners cells blank at #4 and 3/4 and its height values at 7/16 and 9/16 break the surrounding progression, so those four sizes should be confirmed against the governing standard at RFQ rather than assumed. Threads, property classes and finishes are not tabulated by either source — state them on the RFQ.
What is the MOQ and lead time for this nut type?
The minimum order quantity is 10,000 pieces. Stock items ship in 3–7 days; non-stock items are confirmed at quotation. Common sizes in this nut type are widely stocked; confirm the exact schedule against quantity and size mix at quotation.
Request a Quote
Get factory-direct pricing from the manufacturer.
What to include in your inquiry
- ✓ Standard and property class (e.g. DIN 912, ISO 4762, class 8.8) — or a drawing for custom parts.
- ✓ Sizes, lengths and thread type (metric or inch).
- ✓ Quantity per size and your target delivery date.
- ✓ Destination country, plus any coating or finish requirement.
- ✓ Any documents you need with the shipment (e.g. mill test certificate) so the quote includes them.
- ✓ Your inquiry goes straight to the factory team by email and gets a reply within 24 hours.
- ✓ Factory-direct pricing
- ✓ Standard and custom specifications
- ✓ Factory-direct export to buyers in Europe, Asia, the Americas and the Middle East
- ✓ Full fastener family support