ASME B18.2.2
Dimensions of the specified commercial selection do not replace a manufacturing drawing or the complete supply specification.
ASME B18.2.2
US hexagon nut UNC / UNF
A hexagon nut for joints using American unified threads. UNC and UNF share one data sheet while retaining distinct pitches, dimensions and configurations.
- Dimensional range
- 1/4–7/8 in
- Thread
- Unified UNC / UNF · TPI
- Configuration
- Regular hexagon · two thread series
Technical drawing
- Dimensions in inches. TPI
- threads per inch
- s
- width across flats
- m
- height. Full-hex series limits; not heavy hex.
Variants and dimensional data
Selection from 1/4 to 7/8 inch. Other sizes and threads on request. UNC and UNF are distinct, non-interchangeable series.
Dimensions in inches. Identification drawing, not a manufacturing drawing.
| Thread (in) | Series | TPI | sMin | sMax | mMin | mMax |
|---|---|---|---|---|---|---|
| 1/4 | UNC | 20 | 0.428 | 0.438 | 0.212 | 0.226 |
| 5/16 | UNC | 18 | 0.489 | 0.5 | 0.258 | 0.273 |
| 3/8 | UNC | 16 | 0.551 | 0.563 | 0.32 | 0.337 |
| 7/16 | UNC | 14 | 0.675 | 0.688 | 0.365 | 0.385 |
| 1/2 | UNC | 13 | 0.736 | 0.75 | 0.427 | 0.445 |
| 9/16 | UNC | 12 | 0.861 | 0.875 | 0.473 | 0.496 |
| 5/8 | UNC | 11 | 0.922 | 0.938 | 0.535 | 0.559 |
| 3/4 | UNC | 10 | 1.088 | 1.125 | 0.617 | 0.665 |
| 7/8 | UNC | 9 | 1.269 | 1.312 | 0.724 | 0.776 |
| 1/4 | UNF | 28 | 0.428 | 0.438 | 0.212 | 0.226 |
| 5/16 | UNF | 24 | 0.489 | 0.5 | 0.258 | 0.273 |
| 3/8 | UNF | 24 | 0.551 | 0.563 | 0.32 | 0.337 |
| 7/16 | UNF | 20 | 0.675 | 0.688 | 0.365 | 0.385 |
| 1/2 | UNF | 20 | 0.736 | 0.75 | 0.427 | 0.445 |
| 9/16 | UNF | 18 | 0.861 | 0.875 | 0.473 | 0.496 |
| 5/8 | UNF | 18 | 0.922 | 0.938 | 0.535 | 0.559 |
| 3/4 | UNF | 16 | 1.088 | 1.125 | 0.617 | 0.665 |
| 7/8 | UNF | 14 | 1.269 | 1.312 | 0.724 | 0.776 |
ASME B18.2.2 identifies geometry. Agree ASTM/SAE specification, grade, thread tolerance and finish for the supply. No automatic equivalence to metric classes 8, 10 or 12.
Table dimensions refer to the stated execution. DIN/UNI, polymer and special variants require verification of their own dimensions; they do not automatically inherit reference geometry, weight or performance.
Materials, classes, finishes and treatments
Executions are distinguished by reference, material, class and finish. DIN, ISO and UNI references do not imply dimensional equivalence or availability of every size in each material. Supply and batch documents require quotation confirmation.
| Execution reference | Material | Class / hardness | Documented finishes |
|---|---|---|---|
| ANSI B18.2.2 | Steel | To be specified | Plain; Yellow zinc plated; Zinc plated |
“To be specified” is a requirement not established by this selection; it does not imply class 70/80, HV hardness or an automatic finish. Steel property classes do not apply to nylon/polyamide; PA6 and PA66 are distinguished only where stated. For nuts with non-metallic inserts, the material shown is the body material.
Documentation
Download Dueemme data sheet ↓| Document | Status |
|---|---|
| Declaration of conformity | Subject to order agreement |
| Material certificate | Subject to order agreement |
| EN 10204 2.2 test report | Subject to order agreement |
| EN 10204 3.1 inspection certificate | Subject to order agreement |
| Dimensional inspection report | Subject to order agreement |
| Coating report | Subject to order agreement |
| Other documentation | Subject to order agreement |
Batch documents are not automatically included: specify your requirements in the RFQ.
ISO, DIN and UNI: key differences
Configure your enquiry
Selections follow the technical combinations in this data sheet. Quantities, delivery terms and documents will be agreed in the quotation.
Other materials, property classes and finishes available on request. Each configuration is assessed against the enquiry specification.
The size you need, including custom specifications
Other diameters, lengths, materials and finishes can be assessed on request. For dedicated production, we agree geometry, requirements and minimum quantities with the customer.
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