| 螺紋牙距表 | |||||||
| 公制螺紋牙距表 | 美製 統一標準螺紋牙數表 | ||||||
| 公稱直徑 | 牙距 mm | 公稱直徑 | 直徑尺寸 | 牙距＝每英寸牙數 | |||
| 毫米 | 粗牙 | 細牙 | 號＜ 1/4" | 英寸 in | 毫米 mm | 粗牙 UNC | 細牙 UNF |
| M1 | 0.25 | 0.2 | 0# | 0.06 | 1.524 | - | 80 |
| M1.2 | 0.25 | 0.2 | 1# | 0.073 | 1.854 | 64 | 72 |
| M1.6 | 0.35 | 0.2 | 2# | 0.086 | 2.184 | 56 | 64 |
| M2 | 0.4 | 0.25 | 3# | 0.099 | 2.515 | 48 | 56 |
| M2.5 | 0.45 | 0.35 | 4# | 0.112 | 2.845 | 40 | 48 |
| M3 | 0.5 | 0.35 | 5# | 0.125 | 3.175 | 40 | 44 |
| M4 | 0.7 | 0.5 | 6# | 0.138 | 3.505 | 32 | 40 |
| M5 | 0.8 | 0.5 | 8# | 0.164 | 4.166 | 32 | 36 |
| M6 | 1 | 0.75 | 10# | 0.19 | 4.826 | 24 | 32 |
| M8 | 1.25 | 1 | 12# | 0.216 | 5.486 | 24 | 28 |
| M10 | 1.5 | 1.25 | 1/4" | 0.25 | 6.35 | 20 | 28 |
| M12 | 1.75 | 1.25 | 5/16" | 0.3125 | 7.938 | 18 | 24 |
| M14 | 2 | 1.5 | 3/8" | 0.375 | 9.525 | 16 | 24 |
| M16 | 2 | 1.5 | 7/16" | 0.4375 | 11.113 | 14 | 20 |
| M18 | 2.5 | 1.5 | 1/2" | 0.5 | 12.7 | 13 | 20 |
| M20 | 2.5 | 1.5 | 9/16" | 0.5625 | 14.288 | 12 | 18 |
| M22 | 2.5 | 1.5 | 5/8" | 0.625 | 15.875 | 11 | 18 |
| M24 | 3 | 2 | 3/4" | 0.75 | 19.05 | 10 | 16 |
| M27 | 3 | 2 | 7/8" | 0.875 | 22.225 | 9 | 14 |
| M30 | 3.5 | 2 | 1" | 1 | 25.4 | 8 | 12 |
| (M33) | 3.5 | 2 | 1-1/8" | 1.125 | 28.575 | 7 | 12 |
| M36 | 4 | 3 | 1-1/4" | 1.25 | 31.75 | 7 | 12 |
| (M39) | 4 | 3 | 1-3/8" | 1.375 | 34.925 | 6 | 12 |
| M42 | 4.5 | 3 | 1-1/2" | 1.5 | 38.1 | 6 | 12 |
| (M45) | 4.5 | 3 | 1-3/4" | 1.75 | 44.45 | 5 | - |
| M48 | 5 | 3 | 2" | 2 | 50.8 | 4.5 | - |
| 螺距（P）：為相鄰牙在中徑線上對應兩點的軸向距離或相鄰牙山或牙谷間的距離。 | |||||||
| 1、公制牙距直接以距離（毫米mm）標識; | |||||||
| 2、對統一標準螺紋，直徑小於1/4英寸的，以號數來標識 | |||||||
