圆上泽文大学 Thread Form American National(Unified,UN)standard Thread series Long 1/2-20UNF-12 Major diameter Threads per inch Coarse Series-UNC Fine Series-UNF Nominal Tensile Minor Tensile- Minor- Maior Threads Stress Diameter Threads Stress Diameter Size Diameter per Inch Area A. Area A。 Per Inch Area A. Area Ar Designation n in2 in2 0 0.0600 80 0.00180 0.00151 0.0730 64 0.00263 0.00218 72 0.00278 0.00237 0.0860 56 0.00370 0.00310 64 0.00394 0.00339 3 0.0990 0.00487 0.00406 56 0.00523 0.00451 0,1120 40 0.00604 0.00496 48 0.00661 0.00566 5 0.1250 0 0.00796 0.00672 4 0.00880 0.00716 6 0.1380 32 0.00909 0.00745 40 0.01015 0.00874 0.1640 32 0.0140 0.01196 36 0.01474 0.01285 圆上泽夫道大学 Thread Profiles ▣UN profiles: 60° H=0.866p 1313 Thread Form  American National (Unified, UN) standard 1/2 - 20UNF – 1½ Major diameter Threads per inch Thread series Long Thread Profiles  UN profiles: