
ISO 2X
ISO 1 ISO 2 ISO 3 ISO 1
ISO 2 ISO 2X ISO 3
ISO 1 ISO 2 ISO 3
ISO 2X ISO 2X Internal threads 5H
ISO 1 ISO 2 ISO 3 Internal threads 6H
ISO 2X
ISO 1 ISO 2 ISO 3
ISO 2X
ISO 1 ISO 2 ISO 3
ISO 2X
ISO 1 ISO 2 ISO 3
ISO 2X
ISO 1 ISO 2 ISO 3
ISO 2X
ISO 1 ISO 2 ISO 3
ISO 2X
ISO 1 ISO 2 ISO 3
ISO 2X
ISO 1 ISO 2 ISO 3
ISO 2X
ISO 1 ISO 2 ISO 3
ISO 2X
ISO 1 ISO 2 ISO 3
ISO 2X
ISO 1 ISO 2 ISO 3
ISO 2X
ISO 1 ISO 2 ISO 3
ISO 2X
ISO 1 ISO 2 ISO 3
UNJ Threads are Unified Threads used for Aircrafts.
In order to protect the breakage from thread bottom of external threads, UNJ thread defines the minor diameter larger than Unified thread and the range of root bottom R. And accuracy of threads is only defined in highest classes of unified threads, 3A of external threads and 3B of internal threads. UNJ Threads were initially defined as a MIL Standard (American Millitary Standard ). It is now superseded by American SAE Standard ( Automobile Engineers Association). Standard Numbers are as follows:
Basic profile of UNJ thread is shown in the drawing below. Truncation on thread root of external threads is 5H/16, that is, H/16 larger than H/4 of normal Unified Thread's truncation. And radius of thread root is 0.18042P~0.15011P.
Internal Threads
External Threads
| H | =0.866025P | D =d | 【reference】 | ||
| H | D | =d | |||
| 1 =9H/16 | 2 | 2 | 9H/16 =0.487139P | ||
| d2 =d-0.649519P | D1 =d1 | H/2 (8H/16)=0.433013P | |||
| d1 =d-0.974278P | P =25.4/n | 5H/16 =0.270633P |
series is larger than that of normal Unified Threads. unit: mm Minor Diameter Size Bored Hole Size Maximum Minimum
| No.6 | - 32 UNJC | 2.938 | 2.734 | 2.89 | |
| No.6 | - 40 UNJF | 3.053 | 2.888 | 3.01 | |
| No.8 | - 32 UNJC | 3.599 | 3.394 | 3.55 | |
| No.8 | - 36 UNJF | 3.662 | 3.480 | 3.62 | |
| No.10 - 24 UNJC | 4.064 | 3.795 | 4.00 | ||
| No.10 - 32 UNJF | 4.254 | 4.054 | 4.20 | ||
| No.12 - 24 UNJC | 4.704 | 4.456 | 4.64 | ||
| No.12 - 28 UNJF | 4.815 | 4.603 | 4.76 | ||
| 1/4 - 20 UNJC | 5.387 | 5.114 | 5.32 | ||
| 1/4 - 28 UNJF | 5.661 | 5.467 | 5.61 | ||
| 5/16 - 18 UNJC | 6.832 | 6.564 | 6.76 | ||
| 5/16 - 24 UNJF | 7.109 | 6.907 | 7.06 | ||
| 3/8 - 16 UNJC | 8.255 | 7.979 | 8.19 | ||
| 3/8 - 24 UNJF | 8.679 | 8.494 | 8.63 | ||
| 7/16 - 14 UNJC | 9.639 | 9.348 | 9.57 | ||
| 7/16 - 20 UNJF | 10.083 | 9.876 | 10.03 | ||
| 1/2 - 13 UNJC | 11.094 | 10.798 | 11.02 | ||
| 1/2 - 20 UNJF | 11.661 | 11.464 | 11.61 |