統一螺紋標準 （UTS） 定義了美國和加拿大常用螺紋的標準螺紋牙型和系列，以及餘量、公差和型號。
它是這些國家/地區使用的螺栓、螺母和各種其他產品的主要標準。它具有與 ISO 公製螺紋相同的 60° 牙型，但每個 UTS 螺紋的特徵尺寸（外徑和螺距）都以分數而不是毫米值的形式選擇。UTS 目前由美國的 ASME/ANSI 控制。
UNC - 統一粗螺紋
| 大小 |
直徑 |
TPS |
節徑 |
外螺紋小直徑 |
內螺紋小直徑 |
| #1 |
0.0730 |
64 |
0.0629 |
0.0544 |
0.0561 |
| #2 |
0.0860 |
56 |
0.0744 |
0.0648 |
0.0667 |
| #3 |
0.0990 |
48 |
0.0855 |
0.0741 |
0.0764 |
| #4 |
0.1120 |
40 |
0.0958 |
0.0822 |
0.0849 |
| #5 |
0.1250 |
40 |
0.1088 |
0.0952 |
0.0979 |
| #6 |
0.1380 |
32 |
0.1177 |
0.1008 |
0.1042 |
| #7 |
0.1640 |
32 |
0.1437 |
0.1268 |
0.1302 |
| #10 |
0.1900 |
24 |
0.1629 |
0.1404 |
0.1449 |
| #12 |
0.2160 |
24 |
0.1889 |
0.1664 |
0.1709 |
| 1/4" |
0.2500 |
20 |
0.2175 |
0.1905 |
0.1959 |
| 5/16" |
0.3125 |
18 |
0.2764 |
0.2464 |
0.2524 |
| 3/8" |
0.3750 |
16 |
0.3344 |
0.3005 |
0.3073 |
| 7/16" |
0.4375 |
14 |
0.3911 |
0.3525 |
0.3602 |
| 1/2" |
0.5000 |
13 |
0.4500 |
0.4084 |
0.4167 |
| 9/16" |
0.5625 |
12 |
0.5084 |
0.4633 |
0.4723 |
| 5/8" |
0.6250 |
11 |
0.5660 |
0.5168 |
0.5266 |
| 3/4" |
0.7500 |
10 |
0.6850 |
0.6309 |
0.6417 |
| 7/8" |
0.8750 |
9 |
0.8028 |
0.7427 |
0.7547 |
| 1" |
1.0000 |
8 |
0.9188 |
0.8512 |
0.8647 |
UNC - 統一粗螺紋
| 大小 |
直徑 |
TPS |
節徑 |
外螺紋小直徑 |
內螺紋小直徑 |
| #0 |
0.0600 |
80 |
0.0519 |
0.0451 |
0.0465 |
| #1 |
0.0730 |
72 |
0.0640 |
0.0565 |
0.0580 |
| #2 |
0.0860 |
64 |
0.0759 |
0.0674 |
0.0691 |
| #3 |
0.0990 |
56 |
0.0874 |
0.0778 |
0.0797 |
| #4 |
0.1120 |
48 |
0.0985 |
0.0871 |
0.0894 |
| #5 |
0.1250 |
44 |
0.1102 |
0.0979 |
0.1004 |
| #6 |
0.1380 |
40 |
0.1218 |
0.1082 |
0.1109 |
| #8 |
0.1640 |
36 |
0.1460 |
0.1309 |
0.1339 |
| #10 |
0.1900 |
32 |
0.1697 |
0.1528 |
0.1562 |
| #12 |
0.2160 |
28 |
0.1928 |
0.1734 |
0.1773 |
| 1/4" |
0.2500 |
28 |
0.2268 |
0.2074 |
0.2113 |
| 5/16" |
0.3125 |
24 |
0.2854 |
0.2629 |
0.2674 |
| 3/8" |
0.3750 |
24 |
0.3479 |
0.3254 |
0.3299 |
| 7/16" |
0.4375 |
20 |
0.4050 |
0.3780 |
0.3834 |
| 1/2" |
0.5000 |
20 |
0.4675 |
0.4405 |
0.4459 |
| 9/16" |
0.5625 |
18 |
0.5264 |
0.4964 |
0.5024 |
| 5/8" |
0.6250 |
18 |
0.5889 |
0.5589 |
0.5649 |
| 3/4" |
0.7500 |
16 |
0.7094 |
0.6763 |
0.6823 |
| 7/8" |
0.8750 |
14 |
0.8286 |
0.7900 |
0.7977 |
| 1" |
1.0000 |
12 |
0.9459 |
0.9001 |
0.9098 |
公製螺紋換算
| 公製粗略 |
公製精細 |
北卡羅來納大學 |
UNF |
| M2 x 0.4 |
- |
1-64 |
1-72 |
| M2.5 x 0.45 |
- |
3-48 |
3-56 |
| M3 x 0.5 |
- |
4-40 |
4-48 |
| M3.5 x 0.6 |
- |
6-32 |
6-40 |
| M4 x 0.7 |
- |
8-32 |
8-36 |
| M5 x 0.8 |
- |
10-24 |
10-32 |
| M6 x 1 |
M6 x 0.75 |
1/4-20 |
1/4-28 |
| M8 x 1.25 |
M8 x 1 |
5/16-18 |
5/16-24 |
| M10 x 1.5 |
M10 x 1.25 |
3/8-16 |
3/8-24 |
| M12 x 1.75 |
M12 x 1.25 |
1/2-13 |
1/2-20 |
| M14 x 2 |
M14 x 1.5 |
9/16-12 |
9/16-18 |
| M16 x 2 |
M16 x 1.5 |
5/8-11 |
5/8-18 |
| M20 x 2.5 |
M20 x 1.5 |
3/4-10 |
3/4-16 |
| M24 x 3 |
M24 x 2 |
1-8 |
1-12 |
| M30 x 3.5 |
M30 x 2 |
1 1/4-7 |
1 1/8-12 |
| M36 x 4 |
M36 x 3 |
1 1/2-6 |
1 1/4-12 |
