PARAMETRIC · 3D · STEP / STL / 3MF
Hex Nut (UNC) 7/16-14 UNCHEX NUT UNC
Free STEP, STL and 3MF download of a hex nut (unc) 7/16-14 UNC with live 3D preview. Key dimensions: Threads per inch 14 TPI, Pitch 1.814 mm, Major diameter 7/16" (11.11 mm), Minor diameter 9.148 mm. Every parameter stays adjustable, and you can send it straight to Orinovate for printing.
- StandardASME B18.2.2
- ThreadUNC 1/4–3/4"
- ThreadSimplified / modeled / print
- OutputSTEP · STL · 3MF · DXF
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CALCULATED · SPEC
AUTO-COMPUTED
n
14TPI
Threads per inch
P
1.814mm
Pitch
D
7/16" (11.11 mm)
Major diameter
D1
9.148mm
Minor diameter
⌀
U (9.35 mm)
Tap drill
dh
0.469" (11.91 mm)
Clearance hole (fine / medium)
F
11/16" (17.46 mm)
Width across flats
G
20.16mm
Width across corners
H
3/8" (9.52 mm)
Nut height
HOW-TO
How to generate a hex nut (unc) STEP / STL file
- 1Pick the UNC size — across-flats F and height H follow ASME B18.2.2.
- 2Choose the internal thread mode.
- 3Check the spec cards and any warnings.
- 4Download STEP, STL or 3MF — or send it to Orinovate for a quote.
What is a UNC hex nut?
ASME B18.2.2 defines inch hex nuts for UNC bolts, found in US machinery, vehicles and camera gear (1/4-20 tripod threads). Nut height is about 7/8 D, with 30° chamfers on both faces.
UNC thread dimensions
ASME B1.1 Unified threads share the 60° ISO profile; pitch P = 25.4 / TPI mm, internal minor D1 = D − 1.0825P, pitch diameter D2 = D − 0.6495P. The model is built in millimetres and the STEP file is in mm — switch units in your CAD to read inches.
Specs at default parameters
| Parameter | Value | Range |
|---|---|---|
| Size (diameter-TPI) | 7/16-14 | 1/4-20 / 5/16-18 / 3/8-16 / 7/16-14 / 1/2-13 / 5/8-11 / 3/4-10 |
| Thread mode | Modeled thread | Simplified (no thread) / Modeled thread / 3D-print thread |
| Print clearance (c) | 0.2 mm | 0.05–0.5 |
| Threads per inch (n) | 14 TPI | — |
| Pitch (P) | 1.814 mm | — |
| Major diameter (D) | 7/16" (11.11 mm) | — |
| Minor diameter (D1) | 9.148 mm | — |
| Tap drill (⌀) | U (9.35 mm) | — |
| Clearance hole (fine / medium) (dh) | 0.469" (11.91 mm) | — |
| Width across flats (F) | 11/16" (17.46 mm) | — |
| Width across corners (G) | 20.16 mm | — |
| Nut height (H) | 3/8" (9.52 mm) | — |
Popular hex nut (unc) sizes
FAQ
How big is a 1/4-20 hex nut?
ASME B18.2.2 hex nuts: 1/4" is 7/16" (11.11 mm) across flats and 7/32" (5.56 mm) thick; 5/16" 1/2" / 17/64"; 3/8" 9/16" / 21/64"; 1/2" 3/4" / 7/16"; 3/4" 1-1/8" / 41/64". Note the 7/16" nut is 11/16" across flats — larger than the 5/8" cap-screw head.
Can UNC and metric screws be mixed? What does 1/4-20 mean?
No. UNC sizes are inch diameter and threads per inch: 1/4-20 = 1/4" (6.35 mm) diameter with 20 TPI (1.27 mm pitch). It is close to M6 (1.0 mm pitch) in diameter but the pitch differs, so forcing one into the other strips the thread. Both use a 60° profile, so the same formulas apply. Camera tripod screws are 1/4-20 UNC.
What tap drill for 1/4-20?
Common UNC tap drills (≈ 75 % thread): 1/4-20 #7 (5.1 mm), 5/16-18 F (6.5 mm), 3/8-16 5/16" (7.9 mm), 7/16-14 U (9.3 mm), 1/2-13 27/64" (10.7 mm), 5/8-11 17/32" (13.5 mm), 3/4-10 21/32" (16.7 mm). Metric substitutes: 5.1 mm for 1/4-20, 8.0 mm for 3/8-16.
How big should a printed hex-nut pocket be?
Make the pocket across-flats s + 0.2–0.3 mm (FDM) and depth m + 0.2 mm. An M3 nut (s 5.5, m 2.4) → 5.75 mm across flats, 2.6 mm deep; an M8 nut (s 13) → 13.25 mm. A side-loading slot keeps the nut captive better.
Do 3D-printed threads work?
Yes, from about M6 up — a 0.4 mm FDM nozzle can barely resolve an M3 thread (0.5 mm pitch). Use the 3D-print mode (external thread shrunk 0.15 mm, internal enlarged 0.2 mm, adjustable), print screws standing up with ≤ 0.12 mm layers. For parts that are assembled often or loaded, heat-set inserts or a captive hex-nut pocket last far longer than printed threads.
Which software opens the hex nut (unc) STEP file?
STEP (AP214) opens in Fusion 360, SolidWorks, FreeCAD, Onshape and Rhino. STL / 3MF import directly into Bambu Studio, PrusaSlicer or Cura.
Is it free?
Yes — no sign-up, no fees. Need a physical part? Send it to Orinovate for an instant quote in FDM, SLA, SLS, MJF or CNC.
Related generators
Need a physical part?
Send the model straight to Orinovate's instant quote: FDM, SLA, SLS, MJF, metal printing and CNC, made in Hsinchu, Taiwan.
About STEP / STL / 3MF / DXF
- STEP (.step / .stp, AP214) keeps exact dimensions and surfaces for editing in Fusion 360, SolidWorks or FreeCAD.
- STL and 3MF are triangle meshes that import directly into Bambu Studio, PrusaSlicer or Cura.
- DXF is the top-view 2D outline, ready for laser cutting, waterjet or CNC routing.
- All models are in millimetres at true scale.