1、螺紋基本尺寸對照表 （以及螺紋底孔相關尺寸）參照機械設計師首冊編制 OPMSM2005年7月螺 紋 代 號 Thread code一、英制螺紋（螺紋牙型角55度）BSW英國標準惠氏螺紋（粗牙）BSF英國標準惠氏螺紋（細牙）G直管螺紋(外螺紋分A、B兩級即在螺紋中徑公差有所區別，絲錐分G、G-D)非密封性螺紋R錐管外螺紋（舊代號ZG；KG）RC錐管內螺紋（舊代號ZG；KG）二、美制螺紋（螺紋牙型角60度） UNC統一制粗牙螺紋（代替NC）UNF統一制細牙螺紋（代替NF）UNEF統一制超細牙螺紋UN統一制不變螺距螺紋UNS統一制特殊螺紋三、美制螺紋（螺紋牙型角60度）NPT一般用途錐管螺紋（舊代號

2、Z、K）（斜角為147即1：16）NPSC管接頭直管內螺紋NPSM設備上自由配合，機械連接用直管螺紋NPTF干密封錐管螺紋NPSF干密封燃料內螺紋NGT氣瓶用螺紋四、米制螺紋（螺紋牙型角60度，斜角為14724即1：16）ZM米制錐管螺紋五、其它螺紋SM縫紉機螺紋（螺紋牙型角60度，平頂、螺紋底部為園弧形）PZ氣瓶螺紋5V1至20V1氣門芯螺紋（螺紋牙型角60度，平頂、螺紋底部為園弧形）六、管螺紋（螺紋牙型角55度，螺紋頂、底部為園弧形約）RC圓錐內螺紋（螺紋牙型角55度，斜角為147即1：16）RP圓柱內螺紋（螺紋牙型角55度）R圓錐外螺紋（螺紋牙型角55度，斜角為147即1：16）七、普通

3、螺紋（螺紋牙型角60度）M普通螺紋代號八、特殊螺紋Tr梯形螺紋（螺紋牙型角30度）B鋸齒形螺紋（牙型角3030度）螺紋公稱直徑d螺距P鉆頭直徑d銅不銹鋼20416160251751753052525035215215407333305353550841420545456149507552528125666717707571721015848512586871697075717212175101102151041051251061071109111421181215124125112913162138141514414511491518251531552158161516416511691720

4、25173175217818151841851189192225193195219820152042051209212432072122182215224225122923非螺紋密封英制英制錐管螺紋英制錐螺紋螺紋直徑牙數鉆頭直徑螺紋直徑牙數鉆頭直徑螺紋直徑牙數鉆頭直徑1/828881/828841/827861/4191171/4191121/4181113/8191523/8191473/8181451/2141891/2141831/2141793/4142443/4142363/41423211130611429711152921-1/4113921-1/4113831-1/411537

5、91-3/8114161-1/2114411-1/21154391-1/211451211558211556螺距(t)螺紋長度基面上螺紋直徑牙型高度(h1)有效長度基面長度外徑(d)中徑(d2)內徑(d1)0.9194.59.739.158.570.581.3411613.1612.311.450.861.3412616.6615.8114.950.861.81157.520.9619.7918.631.161.81179.526.4425.2824.121.162.31191133.2531.7730.291.482.31221341.9140.4338.951.482.31231447.8

6、146.3344.851.482.31261659.6258.1456.661.482.313018.575.1973.7172.231.482.313220.587.8986.4184.931.482.313825.5113.03111.56110.081.48本螺紋基面上各直徑等于圓柱螺紋的各相應直徑基面上螺紋內徑 d1 = d - 1.28t3/4 = 26.44 - 1.28 * 1.81 = 24.12斜角（）14724 錐角 （2tg)=1:16公稱直徑（英寸）每英寸牙數（n)螺距(t)管子外徑（d)管接頭螺紋內徑（d1)牙型高度(h1)名義尺寸最大外徑最小外徑名義尺寸最大內徑最小

7、內徑 1/8280.919.739.689.388.578.928.670.58 1/4191.3413.1613.112.7411.4511.8411.560.86 3/8191.3416.6616.616.2414.9515.3515.060.86 1/2141.8120.9620.8920.518.6319.0518.751.16 5/8141.8122.9122.8522.4620.5921.0120.711.16 3/4141.8126.4426.3825.9724.1224.5724.251.167/8141.8130.230.1429.7327.8828.3328.011.161

8、112.3133.2533.1832.7530.2930.7930.431.481-1/4112.3141.9141.8441.3638.9539.4639.11.481-3/8112.3144.3344.2643.7841.3741.8741.511.481-1/2112.3147.8147.7447.2144.8545.4451.481-3/4112.3153.7553.6753.1450.7951.3450.941.482112.3159.6259.5459.0156.6657.2156.811.482-1/2112.3175.1975.1174.5472.2372.8372.391.4

9、83 112.3187.8987.887.1984.9385.5885.11.48外徑d由公稱直徑所決定螺紋內徑 d1 = d - 1.28t斜角（）14724 錐角 （2tg)=1:16公稱直徑（英寸）每英寸牙數（n)螺距(t)螺紋長度基面上螺紋直徑牙型高度(h1)有效長度基面長度外徑(d)中徑(d2)內徑(d1)1/16270.946.54.067.97.146.390.751/8270.9474.5710.279.528.770.751/4181.419.55.0813.5712.4411.311.133/8181.4110.56.117.0615.9314.81.131/2141.81

10、13.58.1321.2219.7718.321.453/4141.81148.6126.5725.1223.671.45111-1/22.2117.510.1633.2331.4629.691.771-1/411-1/22.211810.6741.9940.2238.451.771-1/211-1/22.2118.510.6748.0546.2944.521.77211-1/22.211911.0760.0958.3356.561.77外徑d由公稱直徑所決定牙型高度 h1=0.8t基面上螺紋內徑 d1 = d - 1.6t3/8 = 17.06mm d1=17.06 - 1.6 * 1.41

11、 = 14.80斜角（）14724 錐角 （2tg)=1:16公稱直徑每寸牙數螺距(t)外螺紋外徑內螺紋內徑選用鉆頭名義尺寸最大尺寸最小尺寸名義尺寸最大尺寸最小尺寸3/16241.064.634.54.243.563.973.713.71/4201.276.26.055.754.915.395.15.15/16181.417.787.627.316.346.866.556.53/8161.599.369.28.97.738.297.977.97/16141.8110.9310.7510.459.069.679.339.31/2122.1212.512.311.910.310.9610.6110

12、.59/16122.1214.0813.8713.4711.8912.5612.212.15/8112.3115.6515.4315.0313.2613.9413.613.53/4102.5418.8118.5718.1716.1716.9216.5416.47/892.8221.9621.721.219.0319.8219.4519.5183.1825.1124.8224.3221.822.6722.27221-1/873.6328.2527.9327.3324.4625.4324.991-1/473.6331.4331.0930.4927.6428.5928.181-3/864.2334.

13、5634.233.630.1331.2330.761-1/264.2337.7337.3636.7633.3134.3833.941-3/455.0844.0243.5942.7938.739.9539.451-7/84.55.6447.1546.6845.8841.2342.5842.0624.55.6450.3249.8449.0444.4145.7945.25內螺紋（d）公稱直徑 3/4=19.05 mm外螺紋（d1） 內徑 d-1.28 t 3/4=19.05 -1.28 * 2.54=15.79 mm外螺紋（d1） 內徑 d-1.134 t 3/4=19.05 -1.134 * 2.54=16.16 mm公稱直徑 （英寸）每英寸牙數（n)螺 距(t)外螺紋外徑內螺紋內徑名義尺寸名義尺寸11/16141.81417.2815.43/8201.279.388.087/8112.312219