美制UN系列螺纹标准.pdf

文档介绍：UNIFIED SCREW THREADS 1735For UNR thread form substitute UNR for UN for external threads 2. Diameter-binations for Standard Series of Threads (UN/UNR)SizesaNo. orInchesaSizes shown in parentheses are secondary sizes. Primary sizes of 41?4, 41?2, 43?4, 5, 51?4, 51?2, 53?4 and 6inches also are in the 4, 6, 8, 12, and 16 thread series; secondary sizes of 41?8, 43?8, 45?8, 47?8, 51?8, 53?8, 55?8,and 57?8 also are in the 4, 6, 8, 12, and 16 thread series. per InchSeries with Graded Pitches Series with Uniform (Constant) PitchesCoarseUNCFinebUNFbFor diameters over 11?2 inches, use 12-thread series. Extra finecUNEFcFor diameters over 111?16 inches, use 16-thread series. 4-UN 6-UN 8-UN 12-UN 16-UN 20-UN 28-UN 32-UN0 …80Series designation shown indicates the UN thread form; however, the UNR thread form may be specified by substituting UNR in place of UN in all designations for external threads.(1) 64 722 56 64(3) 48 564 40 485 40 44………………………6 32 40……………………UNC8 32 36……………………UNC10 24 32……………………UNF(12) 24 28 32………………UNF UNEF1? 20 28 32……………UNC UNF UNEF5? 18 24 32……………20 28 UNEF3? 16 24 32…………UNC 20 28 UNEF7? 14 20 28…………16 UNF UNEF 321? 13 20 28…………16 UNF UNEF 329? 12 18 24………UNC 16 20 28 325? 11 18 24………12 16 20 28 32(11?16)……24………12 16 20 28 323? 10 16 20………12 UNF UNEF 28 32(13?16)……20………12 16 UNEF 28 327? 9 14 20………12 16 UNEF 28 32(15?16)……20………12 16 UNEF 28 321 8 12 20……UNC UNF 16 UNEF 28 32(11?16)……18……812162028…11? 7 12 18……8 UNF 16 20 28…(13?16)……18……812162028…11? 7 12 18……8 UNF 16 20 28…15?……18……812162028…13? 6 12 18…UNC 8 UNF 16 20 28…(17?16)……18…6 8 12 16 20 28…11? 6 12 18…UNC 8 UNF 16 20 28…(19?16)……18…6