美制螺纹底孔直径表

公 制,英 制,美 制 螺 纹 标 准
公制标准牙
公制幼牙
尺寸
英制标准牙 BSW
英制幼牙 BSF
美制标准牙 UNC
美制幼牙 UNF
美制幼牙 UNEF
尺寸 牙距(MM) 底孔直径(MM) 尺寸 牙距(MM) 底孔直径(MM) 尺寸 牙距(MM) 底孔直径(MM) 英制(tach) 牙距(per inch) 底孔直径(MM) 牙距(per inch) 底孔直径(MM) 牙距(per inch) 底孔直径(MM) 牙距(per inch) 底孔直径(MM) 牙距(per inch) 底孔直径(MM)
34
1.1/2
6
M20 2.5
17.5
1
14
3
33
1.5/8
5
M15
M22 2.5
19.5
1.5
13.5 M38 1.5 36.5
1.3/4
5
M24 3 M27 3
21
1
15
1.5
37.5
1.7/8
4.5
M16
24
1.5
14.5 M39 2
37
2"
4.5
M30 3.5 M33 3.5
26.5 29.5
美制小牙孔标准牙(NC)
牙距(per inch) 底孔直径(MM) 底孔深度(MM)
64
1.5(1.55)
5
56
1.8(1.85)
6
48
2.1
7
40
2.3(2.35)
8
40
2.6(2.65)
9
32
2.8(2.85)
10
32
3.5

美制外螺纹（2A）常用规格极限尺寸表（粗牙）
1.螺胚直径指滚丝前的尺寸，数值为依经验公式计算而得，在实践中需验证。

2.标记示例：10-24UNC-2A（或0.190-24UNC-2A）、3/8-16UNC-2A（或0.375-16UNC-2A）（注：表中上行斜体数值单位为英寸，下行为毫米）
美制外螺纹（2A）常用规格极限尺寸表（细牙）
1.螺胚直径指滚丝前的尺寸，数值为依经验公式计算而得，在实践中需验证
2.标记示例：10-32UNF-2A(或0.190-32UNF-2A)、3/8-24UNF-2A(或0.375-24UNF-2A)
美制内螺纹（2B）常用规格极限尺寸表（粗牙）
1.底孔直径指攻丝前钻孔直径，铸铁、黄铜等较软料取小值，钢、青铜等较硬料取大值。

2.标记示例：10-24UNC-2B(或0.190-24UNC-2B)、3/8-16UNC-2B(或0.375-16UNC-2B)
美制内螺纹（2B）常用规格极限尺寸表（细牙）
1.底孔直径指攻丝前钻孔直径，铸铁、黄铜等较软料取小值，钢、青铜等较硬料取大值。

2.标记示例：10-32UNF-2B(或0.190-32UNF-2B)、3/8-24UNF-2B(或0.375-24UNF-2B)。

8
83
18
6.6
16
8
14
9.4
13
10.8
12
12.2
11
13.5
10
16.5
9
19.5
8
22.25
7
25
7
28
6
30.75
6
34
5
39.5
4.5
45
4.5
51.5
4
57.25
4
63.5
4
70
28
5.5
24
6.9
24
8.5
20
9.9
20
11.5
18
12.9
18
14.5
16
17.5
14
20.4
12
23.25
M1 0.25 0.7(0.75) M2.5 0.35 2.1(2.15)
1
23
1/16
60
M1.1 0.25 0.8(0.85) M3 0.35 2.6(2.65) M24 1.5 22.5
3/32
48
M1.2 0.25 0.9(0.95) M3.5 0.35 3.1(3.15)
2
22
1/8
40
M1.4 0.3
编号
#0-80 #1-72 #2-64 #3-56 #4-48 #5-44 #6-40 #8-36 #10-32 #12-28
美制小牙孔幼牙(NC)
牙距(per inch) 底孔直径(MM) 底孔深度(MM)
80
1.2(1.25)
4
72
1.5(1.55)
5
64

公制标准牙公制幼牙尺寸牙距(MM)底孔直径(MM)尺寸牙距(MM)底孔直径(MM)尺寸牙距(MM)底孔直径(MM)M10.250.7(0.75)M1.10.250.8(0.85)M1.20.250.9(0.95)M1.40.31.1M1.60.351.2(1.25)M1.80.351.4(1.45)M20.41.6M2.20.451.7(1.75)M2.50.452.0(2.05)M30.52.5M3.50.62.9M40.73.3M4.50.753.7M50.84.2M615M716M81.256.8M91.257.8M101.58.5M111.59.5M121.7510.2M14212M16214M182.515.5M202.517.5M222.519.5M24321M27324M303.526.5M333.529.5M36432M39435M424.537.5M454.540.5M48543M52547M565.550.5M2.50.352.1(2.15)M30.352.6(2.65)M3.50.353.1(3.15)M40.53.5M4.50.54M50.54.5M5.50.55M60.755.2M70.756.2M80.757.217M90.758.218M100.759.2191.258.8M110.7510.2110M121111.2510.81.510.5M141131.2512.81.512.5M151141.513.5M161151.514.5M171161.515.5M181171.516.5216M201191.518.5218M22121M241231.522.5222124M251.523.5223126M271.525.5225127M281.526.5226129M301.528.5228327M321.530.52301.531.5M33231330M351.533.51.534.5M36234333M381.536.5M39 1.537.5237336M401.538.5238337M421.540.52403394381.543.51/16601.153/32481.81/8402.65/32323.13/16243.67/32244.41/4205.19/32205.81.520.5220M45243342441尺寸英制标准牙BSW英制幼牙BSF 美制标准牙UNC 美制幼牙UNF 美制幼牙UNEF英制喉牙G,BSP英制锥喉牙Rc,BSPT 美制喉牙NPS 美制锥喉牙NPT英制(tach)牙距(per inch)底孔直径(MM)牙距(per inch)底孔直径(MM)牙距(per inch)底孔直径(MM)牙距(per inch)底孔直径(MM)牙距(per inch)底孔直径(MM)牙距(per inch)底孔直径(MM)牙距(per inch)底孔直径(MM)牙距(per inch)底孔直径(MM)牙距(per inch)底孔直径(MM)5/16186.53/8167.97/16149.31/21210.59/1612121113.511/1611153/4106.513/1610187/8919.25920.751"8221.1/8724.751.1/4727.751.3/8630.51.1/2633.51.5/8535.51.3/45391.7/84.541.55/82"4.544.52.1/44502.1/2456.52.3/43.5623"3.568.5324284.7265.4266.2226.8208.3189.81611.21612.714141415.7512171218.511201121.751023926929832835837.5740743746.5652658.5664.5569.75205.1186.6168149.41310.81212.21113.51016.5919.5822.25725728630.75634539.54.5454.551.5457.25463.5470285.5246.9248.5209.92011.51812.91814.51617.51420.41223.251226.51229.51232.751236325.5327.1328.62810.12811.724132414.752017.52019.252020.752022.252023.751826.751830183318362416.25288.8288.6278.51911.81911.518111915.2519151814.514191418.5141814211424.5142414231428.251130.751130.2511.5291818141411.511.51518.52430278.91135.51139.5113911.53811.53911421145114511.54411.5451149.611571156.511.55611.5571163.31179.111511172.81171.48678681185.5883884美制小牙孔标准牙(NC)美制小牙孔幼牙(NC)牙距(per inch)编号底孔直径(MM)底孔深度(MM)螺纹深度(MM)牙距(per inch)编号底孔直径(MM)底孔深度(MM)螺纹深度(MM)64#1-641.5(1.55)5456#2-561.8(1.85)6448#3-482.175402.3(2.35)8640#5-402.6(2.65)9632#6-322.8(2.85)10732#8-323.511824#10-243.9131024#12-244.51511#4-4080#0-801.2(1.25)4372#1-721.5(1.55)5464#2-641.964562.1(2.15)7548#4-482.48644#5-442.79640#6-402.9(2.95)10736#8-363.511832#10-324.11310#3-5628#12-284.71511制订:审核:日期:公制,英制,美制螺纹标准谢敬锋。