MAN4MACHINE#10-24 UNC
Unified National Coarse
The everyday inch fastener thread. Deeper and stronger to strip out of soft materials than UNF at the same diameter, and the first series to reach for unless a print specifically calls for fine or extra-fine.
- Standard
- ASME B1.1
- Flank angle
- 60° included
- TPI
- 24
- Major diameter
- 0.1900" (basic)
- Other series, same size
Thread profile
A 60 degree included flank angle.
Basic major 0.1900", pitch diameter 0.1629", minor diameter 0.1449" -- theoretical dimensions before any tolerance class is applied.
UNC sizes
| Size | TPI | Major Ø | Pitch Ø | Minor Ø |
|---|---|---|---|---|
| #1 | 64 | 0.0730" | 0.0629" | 0.0561" |
| #2 | 56 | 0.0860" | 0.0744" | 0.0667" |
| #3 | 48 | 0.0990" | 0.0855" | 0.0764" |
| #4 | 40 | 0.1120" | 0.0958" | 0.0849" |
| #5 | 40 | 0.1250" | 0.1088" | 0.0979" |
| #6 | 32 | 0.1380" | 0.1177" | 0.1042" |
| #8 | 32 | 0.1640" | 0.1437" | 0.1302" |
| #10 | 24 | 0.1900" | 0.1629" | 0.1449" |
| #12 | 24 | 0.2160" | 0.1889" | 0.1709" |
| 1/4 | 20 | 0.2500" | 0.2175" | 0.1959" |
| 5/16 | 18 | 0.3125" | 0.2764" | 0.2524" |
| 3/8 | 16 | 0.3750" | 0.3344" | 0.3073" |
| 7/16 | 14 | 0.4375" | 0.3911" | 0.3602" |
| 1/2 | 13 | 0.5000" | 0.4500" | 0.4167" |
| 9/16 | 12 | 0.5625" | 0.5084" | 0.4723" |
| 5/8 | 11 | 0.6250" | 0.5660" | 0.5266" |
| 3/4 | 10 | 0.7500" | 0.6850" | 0.6417" |
| 7/8 | 9 | 0.8750" | 0.8028" | 0.7547" |
| 1 | 8 | 1.0000" | 0.9188" | 0.8647" |
| 1-1/8 | 7 | 1.1250" | 1.0322" | 0.9704" |
| 1-1/4 | 7 | 1.2500" | 1.1572" | 1.0954" |
| 1-3/8 | 6 | 1.3750" | 1.2667" | 1.1946" |
| 1-1/2 | 6 | 1.5000" | 1.3917" | 1.3196" |
| 1-3/4 | 5 | 1.7500" | 1.6201" | 1.5335" |
| 2 | 4.50 | 2.0000" | 1.8557" | 1.7594" |
Did you know
America answers with 60 degrees
In 1864, engineer William Sellers proposed a competing American thread to the Franklin Institute: a simpler 60 degree angle with a flat crest and root, easier to cut and gauge than Whitworth's rounded form. It became the United States Standard (USS) thread, and its 60 degree angle is the direct ancestor of today's Unified and ISO metric threads.
William Sellers, 1864Tap drill calculator
Try “1/4-20 UNC-2A”, “#10-32 UNF”, or “1-8 UN-3A”. Add “LH” for a left-hand thread.
Basic (theoretical) dimensions and a shop tap drill only -- ASME B1.1's exact Class 1A/2A/3A pitch diameter limits depend on length of thread engagement as well as grade. Consult the standard or a calibrated thread gauge for gauge-critical work.
Calculated live
Basic dimensions
- Major diameter
- 0.1900"
- Pitch diameter
- 0.1629"
- Minor diameter
- 0.1449"
Clearance (normal)
- Clearance drill
- #2 (0.2213")
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