螺纹下孔径表
螺紋下孔徑表
公制粗牙螺紋 JIS B 0209-1982(單位:mm)
崁合度區分:中(注1)
2級(注2)
下孔徑
最小直徑最大直徑
M 1 × 0.250.750.78 (80%)0.7290.7851.1 × 0.250.850.88 (80%)0.8290.8851.2 × 0.250.950.98 (80%)0.9290.9851.4 × 0.3 1.1 1.14 (80%) 1.075 1.1421.6 × 0.35 1.25 1.32 (75%) 1.221 1.3211.8 × 0.35 1.45 1.52 (75%) 1.421 1.5212 × 0.4 1.6 1.65 (80%) 1.567 1.6792.2 × 0.45 1.75 1.83 (75%) 1.713 1.8382.5 × 0.45 2.1 2.13 (75%) 2.013 2.1383 × 0.5 2.5 2.59 (75%) 2.459 2.5993.5 × 0.6 2.9 3.01 (75%) 2.85 3.014 × 0.7 3.3 3.39 (80%) 3.242 3.4224.5 × 0.75 3.8 3.85 (80%) 3.688 3.8785 × 0.8 4.2 4.31 (80%) 4.134 4.3346 × 15 5.13 (80%) 4.917 5.1537 × 16 6.13 (80%) 5.917 6.1538 × 1.25 6.8 6.85 (85%) 6.647 6.9129 × 1.257.87.85 (85%)7.6477.91210 × 1.58.58.62 (85%)8.3768.67611 × 1.59.59.62 (85%)9.3769.67612 × 1.7510.310.40 (85%)10.10610.44114 × 21212.2 (85%)11.83512.2116 × 21414.2 (85%)13.83514.2118 × 2.515.515.7 (85%)15.29415.74420 × 2.517.517.7 (85%)17.29417.74422 × 2.519.519.2 (85%)19.29419.74424 × 32121.2 (85%)20.75221.25227 × 32424.2 (85%)23.75224.25230 × 3.526.526.6 (90%)26.21126.77133 × 3.529.529.6 (90%)29.21129.77136 × 43232.1 (90%)31.6732.2739 × 43535.1 (90%)34.6735.2742 × 4.537.537.6 (90%)37.12937.79945 × 4.540.540.6 (90%)40.12940.79948 × 5
43
43.1 (90%)
42.58743.297螺紋尺寸
鑽頭直徑
崁合度區分:中(註1)2級(註2)
內螺紋小徑
管螺纹的分类及换算
尺寸代号每英寸牙数螺距螺纹直径
(in) n p 大径D、d 小径D1、d1
1/16 28 0.907 7.723 6.561
1/8 28 0.907 9.728 8.566
1/4 19 1.337 13.157 11.445
3/8 19 1.337 16.662 14.95
1/2 14 1.814 20.955 18.631
5/8 14 1.814 22.911 20.587
3/4 14 1.814 26.441 24.117
7/8 14 1.814 30.201 27.877
1 11 2.309 33.249 30.291
1-1/8 11 2.309 37.897 34.939
1-1/4 11 2.309 41.91 38.952
1-1/2 11 2.309 47.803 44.845
1-3/4 11 2.309 53.746 50.788
2 11 2.309 59.614 56.656
2-1/4 11 2.309 65.71 62.752
2-1/2 11 2.309 75.184 72.226
2-3/4 11 2.309 81.534 78.578
3 11 2.309 87.88
4 84.926
3-1/2 11 2.309 100.33 97.372
4 11 2.309 113.03 110.072
5 11 2.309 138.43 135.472
6 11 2.309 163.83 160.872
注:1in=25.4mm
1、用螺纹密封的管螺纹其标记及各种螺纹的特征代号规定如下:Rc—圆锥内螺纹
Rp—与圆锥外螺纹配合的圆柱内螺纹
R—圆锥外螺纹
标准规定将螺纹尺寸代号写在特征代号之后,若螺纹为械旋应再加写左旋代号LH,具体示例如下:
圆锥内螺纹:Rc1/2
左旋圆柱内螺纹:Rp1/2—LH
圆柱内螺纹与圆锥外螺纹的配合:Rp2/R2
2、非螺纹密封的管螺纹标记如下:
A级外螺纹:G1/2A
内螺纹:G1/2
左旋B级外螺纹:G1/2B—LH
螺纹副G1/2G1/2A
规格外径mm1英寸=25.4mm,一分管是1/8英寸,二分管是2/8英寸----- 八分管是1英寸。DN16:4分 1/2英寸 21.3 1/8=3.175mm,2/8=1/4=6.350mm,
DN20:6分 3/4英寸 26.93/8=9.525 mm,4/8=1/2=12.7 mm,
DN25:1英寸 33.75/8=15.875mm,6/8=3/4=19.05 mm,
DN32:1.25英寸 42.47/8=22.225mm,8/8=1=25.4mm。
DN40:1.5英寸 48.3管子内径取近似整数。
DN50:2.0英寸 60.3
DN65:2.5英 76.1
DN80:3英寸 88.9
DN100:4英寸 114.3
DN125:5英寸 140
DN150:6英寸 168.3
DN200:8英寸 219.1