ASME B18.2.1 1/4-20 UNC x 1 Hex Cap Screw
In stock in 6 material, grade and finish combinations.
Dimensions at 1/4-20 UNC x 1
in · ASME B18.2.1 · 2012 (R2021) edition| Dimension | Nominal | Min | Max | |
|---|---|---|---|---|
| d | Thread size | 1/4-20 UNC | – | – |
| L | Length | 1 | – | – |
| Basic major diameter | 0.25 | – | – | |
| TPI | Threads per inch | 20 | – | – |
| Thread series | UNC | – | – | |
| Thread class | 2A | – | – | |
| E | Body diameter | – | 0.245 | 0.25 |
| F | Width across flats | – | 0.428 | 0.438 |
| G | Width across corners | – | 0.488 | 0.505 |
| H | Head height | – | 0.15 | 0.163 |
| J | Wrenching height | – | 0.106 | – |
| LT | Thread length (L≤6 in) | 0.75 | – | – |
| LT | Thread length (L>6 in) | 1 | – | – |
- Length under head
- 1 in
- Approx. weight
- ≈ 8.52 kg per 1 000 pieces · Bare steel, before coating and packing.117 pieces per kg
Holes for this thread
ISO 273 · ISO 2306Tap drill#7 (0.2010 in)
Other lengths in 1/4-20 UNC
All 143 sizes of Hex Cap Screw ASME B18.2.1StandardsASME B18.2.1All sizes