Side-by-Side Comparison
Imperial Threads (UNC/UNF)
1/2"-13 UNC vs. #10-24 UNC
Comparing 2 standards across 9 specifications. 9 key differences identified.
Comparing:
1/2"-13 UNC
#10-24 UNC
1/2"-13 UNC is a heavy fractional Unified Coarse bolt thread with a major diameter of 0.5000 inches (12.700 mm) and 13 threads per inch (TPI). Requiring a 27/64 inch (0.4219 inch) tap drill, it is the standard structural fastener for automotive engine cradles, trailer hitches, and building timber connections.
10-24 UNC is a numbered Unified Coarse machine screw thread with a major diameter of 0.1900 inches (4.826 mm) and 24 threads per inch (TPI). Requiring a #25 (0.1495 inch) tap drill, it provides high clamping torque for household appliances, outdoor power equipment, and light mechanical assemblies.
Specification Comparison Table
9 Parameters| Parameter / Spec | ||
|---|---|---|
|
Nominal Major Diameter
|
0.5000 in (12.700 mm) | 0.1900 in (4.826 mm) |
|
Threads Per Inch (TPI)
|
13 TPI (Coarse pitch: 1.954 mm) | 24 TPI (Coarse pitch: 1.058 mm) |
|
Fine Pitch Equivalent
|
1/2"-20 UNF (1.270 mm pitch — standard automotive wheel lugs) | #10-32 UNF (0.794 mm pitch — widely used in 19" AV racks) |
|
Minor Diameter (Internal)
|
0.4167 in (10.584 mm) | 0.1449 in (3.680 mm) |
|
Tensile Stress Area
|
0.1419 in² (91.5 mm²) | 0.0175 in² (11.3 mm²) |
|
Recommended Tap Drill Size
|
27/64 in drill bit (0.4219 in / 10.72 mm) | — |
|
Common Drive Size
|
3/4" Hex (19.05 mm) / 3/8" Allen | — |
|
Tap Drill Size (UNC)
|
— | #25 drill bit (0.1495 in / 3.80 mm) |
|
Tap Drill Size (#10-32 UNF)
|
— | #21 drill bit (0.1590 in / 4.04 mm) |