公称 螺纹 牙 牙 螺 公差 螺纹 外径 螺纹 中径 螺纹小径 公差 螺纹 小径 螺纹 中径 螺纹外径 钻孔直径 规格 数 高 距 代号 Max Min Max Min Max 代号 Min Max Min Max Min 直径0.073（ #1） 1-64UNC 64 0.236 0.397 2A 1.83896 1.74244 1.58242 1.53162 1.36652 2B 1.42494 1.58242 1.59766 1.6637 1.8542 1.3971.854 3A 1.8542 1.75768 1.59766 1.55956 1.38176 3B 1.42494 1.58242 1.59766 1.64592 1.8542 1.3971-72UNF 72 0.21 0.353 2A 1.83896 1.75006 1.61036 1.5621 1.41986 2B 1.4732 1.6129 1.6256 1.6891 1.8542 1.51133A 1.8542 1.7653 1.6256 1.59004 1.4351 3B 1.4732 1.6129 1.6256 1.67386 1.8542 1.51130.086(#2) 2-56UNC 56 0.271 0.454 2A 2.16916 2.06502 1.87452 1.82118 1.63068 2B 1.69418 1.87198 1.88976 1.96088 2.1844 1.70182.184 3A 2.1844 2.08026 1.88976 1.84912 1.64592 3B 1.69418 1.87198 1.88976 1.9431 2.1844 1.70182-64UNF 64 0.236 0.397 2A 2.16916 2.07264 1.91262 1.86182 1.69672 2B 1.75514 1.91262 1.92786 1.99644 2.1844 1.7783A 2.1844 2.08788 1.92786 1.88976 1.71196 3B 1.75514 1.91262 1.92786 1.97866 2.1844 1.7780.099(3#) 3-48UNC 48 0.315 0.529 2A 2.49682 2.38252 2.15392 2.0955 1.86436 2B 1.94056 2.1463 2.1717 2.2479 2.5146 1.99392.515 3A 2.5146 2.4003 2.1717 2.12852 1.88214 3B 1.94056 2.1463 2.1717 2.22758 2.5146 1.99393-56UNF 56 0.271 0.454 2A 2.49682 2.39268 2.20218 2.1463 1.95834 2B 2.02438 2.1971 2.21996 2.29108 2.5146 2.05743A 2.5146 2.41046 2.21996 2.17932 1.97612 3B 2.02438 2.1971 2.21996 2.2733 2.5146 2.05740.112(#4) 4-40UNC 40 0.378 0.635 2A 2.82448 2.69494 2.413 2.3495 2.06756 2B 2.15646 2.38506 2.43332 2.51714 2.8448 2.18442.845 3A 2.8448 2.71526 2.43332 2.38506 2.08788 3B 2.15646 2.38506 2.43332 2.49428 2.8448 2.18444-48UNF 48 0.315 0.529 2A 2.82702 2.71272 2.48412 2.42316 2.19456 2B 2.27076 2.45872 2.5019 2.58064 2.8448 2.26063A 2.8448 2.7305 2.5019 2.45618 2.21234 3B 2.27076 2.45872 2.5019 2.56032 2.8448 2.26060.125(#5) 5-40UNC 40 0.378 0.635 2A 3.15468 3.02514 2.7432 2.67716 2.39776 2B 2.48666 2.69748 2.76352 2.84734 3.175 2.52733.175 3A 3.175 3.04546 2.76352 2.71526 2.41808 3B 2.48666 2.69748 2.76352 2.82702 3.175 2.52735-44UNF 44 0.344 0.577 2A 3.15722 3.0353 2.7813 2.7178 2.46888 2B 2.55016 2.74066 2.79908 2.88036 3.175 2.57813A 3.175 3.05308 2.79908 2.75082 2.48666 3B 2.55016 2.74066 2.54508 2.86004 3.175 2.57810.138(#6 ） 6-32UNC 32 0.472 0.794 2A 3.48488 3.33248 2.96926 2.89814 2.54 2B 2.6416 2.8956 2.98958 3.08356 3.5052 2.70513.505 3A 3.5052 3.3528 2.98958 2.93624 2.56032 3B 2.6416 2.8956 2.98958 3.05816 3.5052 2.70516-40UNF 40 0.378 0.635 2A 3.48488 3.35534 3.0734 3.00736 2.72796 2B 2.8194 3.0226 3.09372 3.18008 3.5052 2.87023A 3.5052 3.37566 3.09372 3.04292 2.74828 3B 2.8194 3.01244 3.09372 3.15722 3.5052 2.87020.164（ #8） 8-32UNC 32 0.472 0.784 2A 4.14274 3.99034 3.62712 3.55346 3.19786 2B 3.302 3.5306 3.64998 3.7465 4.1656 3.45444.166 3A 4.1656 4.0132 3.64998 3.5941 3.22072 3B 3.302 3.52806 3.64998 3.7211 4.1656 3.45448-36UNF 36 0.421 0.706 2A 4.14528 4.00558 3.68808 3.61696 3.30454 2B 3.4036 3.6068 3.7084 3.79984 4.1656 3.4544UN 美制螺纹尺寸 Unit=mm外螺纹尺寸 内螺纹尺寸3A 4.1656 4.0259 3.7084 3.65506 3.32486 3B 3.4036 3.59664 3.7084 3.77698 4.1656 3.45440.19 （ #10） 10-24UNC 24 0.63 1.058 2A 4.8006 4.61772 4.11226 4.02844 3.54076 2B 3.683 3.9624 4.13766 4.24688 4.826 3.73384.826 3A 4.826 4.64312 4.13766 4.07416 3.56616 3B 3.683 3.9497 4.13766 4.21894 4.826 3.733810-28UNS 28 0.54 0.907 2A 4.8006 4.6355 4.21132 4.1275 3.71856 2B 3.8354 4.064 4.23672 4.34594 4.826 3.860810-32UNF 32 0.472 0.784 2A 4.80314 4.65074 4.28752 4.21132 3.85826 2B 3.9624 4.1656 4.31038 4.40944 4.826 3.98783A 4.826 4.6736 4.31038 4.25196 3.88112 3B 3.9624 4.16814 4.31038 4.38404 4.826 3.987810-36UNS 36 0.421 0.706 2A 4.80314 4.66344 4.34594 4.26974 3.9624 2B 4.064 4.2164 4.3688 4.46786 4.826 4.038610-40UNS 40 0.378 0.635 2A 4.80314 4.6736 4.39166 4.318 4.04368 2B 4.1402 4.2926 4.41452 4.5085 4.826 4.089410-48UNS 48 0.315 0.529 2A 4.80568 4.69138 4.46278 4.39674 4.17576 2B 4.2418 4.3688 4.4831 4.56946 4.826 4.216410-56UNS 56 0.271 0.454 2A 4.80822 4.70408 4.51358 4.45008 4.26974 2B 4.3434 4.445 4.53136 4.61264 4.826 4.30530.216（ #12） 12-24UNC 24 0.63 1.058 2A 5.461 5.27812 4.77266 4.6863 4.20116 2B 4.3434 4.5974 4.79806 4.90982 5.4864 4.49580.486 3A 5.4864 5.30352 4.79806 4.73202 4.22656 3B 4.3434 4.58978 4.79806 4.88188 5.4864 4.495812-28UNF 28 0.54 0.907 2A 5.461 5.2959 4.87172 4.79044 4.37896 2B 4.4958 4.7244 4.89712 5.0038 5.4864 4.5723A 5.4864 5.3213 4.89712 4.83616 4.40436 3B 4.4958 4.71678 4.89712 4.97586 5.4864 4.57212-32UNEF 32 0.472 0.784 2A 5.46354 5.31114 4.94792 4.86918 4.51866 2B 4.6228 4.826 4.97078 5.07492 5.4864 4.5723A 5.4864 5.334 4.97078 4.90982 4.54152 3B 4.6228 4.8133 4.97078 5.04952 5.4864 4.57212-36UNS 36 0.421 0.706 2A 5.46354 5.32384 5.00634 4.93014 4.87934 2B 4.7244 4.8768 5.0292 5.12826 5.4864 4.800612-40UNS 40 0.378 0.635 2A 5.46354 5.334 5.05206 4.9784 4.6609 2B 4.8006 4.953 5.07492 5.1689 5.4864 4.851412-48UNS 48 0.315 0.529 2A 5.46608 5.35178 5.12318 5.05714 4.83616 2B 4.9022 5.0292 5.1435 5.22986 5.4864 4.978412-56UNS 56 0.271 0.454 2A 5.46862 5.36448 5.17398 5.1104