螺纹

英制螺纹尺寸公差表

                                                                                单位：毫米

	规格代号	系列  代号	等级	螺距	外螺纹			内螺纹
	名义直径   每英寸牙数				外径	中径	内径	小径	中径	大径
1	0.060—80 （0#—80） 3/50-80	UNF	2	0.3175	1.5113   –0.08128	1.30556  –0.04572	1.12268	1.1811  +0.12446	1.3182   +0.05842	1.524
			3	0.3175	1.5240  –0.08128	1.3182   –0.03302	1.13538	1.1811  +0.12446	1.3182   +0.04318	1.524
2	0.073—64 （1#—64）	UNC	2	0.396875	1.83896  –0.09652	1.58242  –0.0508	1.35128	1.42494 +0.15748	1.59766  +0.06604	1.8542
			3	0.396875	1.8542   –0.09652	1.59766   –0.0381	1.36652	1.42494 +0.15748	1.59766  +0.04826	1.8542
3	0.073—72 （1#—72） 73/1000-72	UNF	2	0.352777	1.83896  –0.0889	1.61036  –0.04826	1.40716	1.4732  +0.1397	1.6256    +0.0635	1.8542
			3	0.352777	1.8542   –0.0889	1.6256   –0.03556	1.4224	1.4732  +0.1397	1.6256   +0.04826	1.8542
4	0.086—56 （2#—56）	UNC	2	0.453571	2.16916  –0.10414	1.87452  –0.05334	1.6129	1.69418  +0.1778	1.88976  +0.07112	2.1844
			3	0.453571	2.1844   –0.10414	1.88976  –0.04064	1.62814	1.69418  +0.1778	1.88976  +0.05334	2.1844
5	0.086—64 （2#—64） 43/500-64	UNF	2	0.396875	2.16916  –0.09652	1.91262  –0.0508	1.68148	1.75514 +0.15748	1.92786  +0.06858	2.1844
			3	0.396875	2.1844   –0.09652	1.92786  –0.0381	1.69672	1.75514 +0.15748	1.92786  +0.0508	2.1844
6	0.099—48 （3#—48）	UNC	2	0.529166	2.49682   –0.1143	2.15392  –0.05842	1.84658	1.94056 +0.20574	2.1717   +0.07620	2.5146
			3	0.529166	2.5146    –0.1143	2.1717   –0.04318	1.86436	1.94056 +0.20574	2.1717   +0.05588	2.5146
7	0.099—56 （3#—56） 99/1000-56	UNF	2	0.453571	2.49682  –0.10414	2.20218  –0.05588	1.94056	2.02438 +0.17272	2.21996  +0.07112	2.5146
			3	0.453571	2.5146   –0.10414	2.21996  –0.04064	1.95834	2.02438 +0.17272	2.21996  +0.05334	2.5146
8	0.112—40 （4#—40）	UNC	2	0.635	2.82448  –0.12954	2.413     –0.0635	2.0447	2.15646  +0.2286	2.43332  +0.08382	2.8448
			3	0.635	2.8448   –0.12954	2.43332  –0.04826	2.06502	2.15646  +0.2286	2.43332  +0.06096	2.8448
9	0.112—48 （4#—48） 14/125-48	UNF	2	0.529166	2.82702   –0.1143	2.48412  –0.06096	2.17678	2.27076 +0.18796	2.5019   +0.07874	2.8448
			3	0.529166	2.8448    –0.1143	2.5019   –0.04572	2.19456	2.27076 +0.18796	2.5019   +0.05842	2.8448
10	0.125—40 （5#—40）	UNC	2	0.635	3.15468  –0.12954	2.7432   –0.06604	2.3749	2.48666 +0.21082	2.76352  +0.08382	3.175
			3	0.635	3.175    –0.12954	2.76352  –0.04826	2.39522	2.48666 +0.21082	2.76352   +0.0635	3.175
11	0.125—44 （5#—44） 1/8	UNF	2	0.577273	3.15722  –0.12192	2.7813    –0.0635	2.44856	2.55016  +0.1905	2.79908  +0.08128	3.175
			3	0.577273	3.175    –0.12192	2.79908  –0.04826	2.46634	2.55016  +0.1905	2.79908  +0.06096	3.175
12	0.138—32 （6#—32）	UNC	2	0.79375	3.48488   –0.1524	2.96926  –0.07112	2.51206	2.6416    +0.254	2.98958  +0.09398	3.5052
			3	0.79375	3.5052    –0.1524	2.98958  –0.05334	2.53238	2.6416    +0.254	2.98958  +0.06858	3.5052
13	0.138—40 （6#—40） 69/500	UNF	2	0.635	3.48488  –0.12954	3.0734   –0.06604	2.7051	2.8194   +0.2032	3.09372  +0.08636	3.5052
			3	0.635	3.5052   –0.12954	3.09372   –0.0508	2.72542	2.8194  +0.19304	3.09372   +0.0635	3.5052

 

序号	规格代号	系列代号	等级	螺距		外螺纹			内螺纹
	名义直径   每英寸牙数				外径	中径	内径	小径	中径	大径
14	0.164—32 （8#—32）	UNC	2	0.79375	4.14274   –0.1524	3.62712  –0.07366	3.16992	3.302   +0.2286	3.64998  +0.09652	4.1656
			3	0.79375	4.1656    –0.1524	3.64998  –0.05588	3.19278	3.302  +0.22606	3.64998  +0.07112	4.1656
15	0.164—36 （8#—36） 41/250-36	UNF	2	0.70555	4.14528   –0.1397	3.68808  –0.07112	3.27914	3.4036  +0.2032	3.7084   +0.09144	4.1656
			3	0.70555	4.1656    –0.1397	3.7084   –0.05334	3.29946	3.4036 +0.19304	3.7084   +0.06858	4.1656
16	0.190—24 （10#—24）	UNC	2	1.05833	4.8006   –0.18288	4.11226  –0.08382	3.50266	3.683   +0.2794	4.13766  +0.10922	4.826
			3	1.05833	4.826    –0.18288	4.13766   –0.0635	3.52806	3.683   +0.2667	4.13766  +0.08128	4.826
17	0.190—32（10#—32） 19/100-32	UNF	2	0.79375	4.80314   –0.1524	4.28752   –0.0762	3.83032	3.9624  +0.2032	4.31038  +0.09906	4.826
			3	0.79375	4.826     –0.1524	4.31038  –0.05842	3.85318	3.9624 +0.20574	4.31038  +0.07366	4.826
18	0.216—24	UNC	2	1.05833	5.461    –0.18288	4.77266  –0.08636	4.16306	4.3434   +0.254	4.79806  +0.11176	5.4864
			3	1.05833	5.4864   –0.18288	4.79806  –0.06604	4.18846	4.3434 +0.24638	4.79806   +0.8382	5.4864
19	0.216—28	UNF	2	0.90714	5.461     –0.1651	4.87172  –0.08128	4.34848	4.4958  +0.2286	4.89712  +0.10668	5.4864
			3	0.90714	5.4864    –0.1651	4.89712  –0.06096	4.37388	4.4958 +0.22098	4.89712  +0.07874	5.4864
20	0.216—32   27/125-32	UNEF	2	0.79375	5.46354   –0.1524	4.94792  –0.07874	4.49072	4.6228  +0.2032	4.97078  +0.10414	5.4864
			3	0.79375	5.4864    –0.1524	4.97078  –0.06096	4.51358	4.6228  +0.1905	4.97078  +0.07874	5.4864
21	0.250—20  1/4—20	UNC	1	1.27	6.32206  –0.30988	5.49656  –0.14224	4.76504	4.9784  +0.2794	5.5245   +0.18542	6.35
			2	1.27	6.32206  –0.20574	5.49656  –0.09398	4.76504	4.9784  +0.2794	5.5245   +0.12446	6.35
			3	1.27	6.35      –0.20574	5.5245   –0.07112	4.79298	4.9784 +0.27178	5.5245   +0.09144	6.35
22	0.250—28   1/4—28	UNF	1	0.90714	6.3246   –0.24892	5.73532    –0.127	5.21208	5.3594  +0.2286	5.76072   +0.1651	6.35
			2	0.90714	6.3246    –0.1651	5.73532  –0.08382	5.21208	5.3594  +0.2286	5.76072  +0.10922	6.35
			3	0.90714	6.35       –0.1651	5.76072   –0.0635	5.23748	5.3594  +0.2032	5.76072  +0.08128	6.35
23	0.250—32   1/4—32	UNEF	2	0.79375	6.3246    –0.1524	5.80898   –0.8128	5.35178	5.4864  +0.2032	5.83438  +0.10668	6.35
			3	0.79375	6.35       –0.1524	5.83438   –0.6096	5.37718	5.4864 +0.17526	5.83438  +0.07874	6.35
24	.3125－18  5/16－18	UNC	1	1.41111	7.90702  –0.33274	6.99008  –0.15494	6.17474	6.4008  +0.3302	7.02056  +0.20066	7.9375
			2	1.41111	7.90702  –0.22098	6.99008   –0.1016	6.17474	6.4008  +0.3302	7.02056  +0.13462	7.9375
			3	1.41111	7.9375   –0.22098	7.02056   –0.0762	6.20522	6.4008  +0.2794	7.02056  +0.09906	7.9375

 

 

 

	序号		规格代号		系列代号		等级		螺距		外螺纹						内螺纹
			名义直径  每英寸牙数								外径		中径		内径		小径		中径		大径
	25		.3125—20  5/16—20		UN		2		1.27		7.90702 –0.20574		7.08152   –0.1016		6.35		6.5532  +0.3048		7.112    +0.13208		7.9375
							3		1.27		7.9375   –0.20574		7.112     –0.0762		6.38048		6.5532   +0.254		7.112    +0.09906		7.9375
	26		.3125—24  5/16—24		UNF		1		1.058333		7.90956  –0.27432		7.22122   –0.1397		6.61162		6.7818   +0.254		7.24916  +0.18034		7.9375
							2		1.058333		7.90956  –0.18288		7.22122  –0.09398		6.61162		6.7818   +0.254		7.24916  +0.12192		7.9375
							3		1.058333		7.9375   –0.18288		7.24916   –0.6858		6.63956		6.7818 +0.21336		7.24916  +0.09144		7.9375
	27		.3125—28  5/16—28		UN		2		0.90714		7.9121    –0.1651		7.32282   –0.8636		6.79958		6.9596  +0.2032		7.34822  +0.11176		7.9375
							3		0.90714		7.9375    –0.1651		7.34822  –0.06604		6.82498		6.9596 +0.17018		7.34822  +0.08382		7.9375
	28		.3125—32  5/16—32		UNEF		2		0.79375		7.9121    –0.1524		7.39648  –0.08128		6.93928		7.0866  +0.1778		7.42188  +0.10668		7.9375
							3		0.79375		7.9375    –0.1524		7.42188  –0.06096		6.96468		7.0866 +0.14478		7.42188   +0.7874		7.9375
	29		0.375—16  3/8—16		UNC		1		1.5875		9.49198  –0.36068		8.46074   –0.1651		7.5438		7.7978  +0.3556		8.49376   +0.2159		9.525
							2		1.5875		9.49198  –0.23876		8.46074  –0.11176		7.5438		7.7978  +0.3556		8.49376  +0.14478		9.525
							3		1.5875		9.525    –0.23876		8.49376  –0.08382		7.57682		7.7978 +0.28448		8.49376  +0.10922		9.525
	30		0.375—20  3/8—20		UN		2		1.27		9.49452  –0.20574		8.66902  –0.10414		7.9375		8.1534  +0.2794		8.6995   +0.13716		9.525
							3		1.27		9.525    –0.20574		8.6995   –0.07874		7.96798		8.1534 +0.22098		8.6995    +0.1016		9.525
	31		0.375—24  3/8—24		UNF		1		1.058333		9.49706  –0.27432		8.80872  –0.14478		8.19912		8.382    +0.254		8.83666 +0.18796		9.525
							2		1.058333		9.49706  –0.18288		8.80872  –0.09652		8.19912		8.382    +0.254		8.83666 +0.12466		9.525
							3		1.058333		9.525    –0.18288		8.83666  –0.07366		8.22706		8.382  +0.18288		8.83666 +0.09398		9.525
	32		0.375—28  3/8—28		UN		2		0.90714		9.49706   –0.1651		8.90778  –0.09144		8.38454		8.5344  +0.2286		8.93572  +0.11684		9.525
							3		0.90714		9.525     –0.1651		8.93572  –0.06858		8.41248		8.5344 +0.16764		8.93572   +0.0889		9.525
	33		0.375—32  3/8—32		UNEF		2		0.79375		9.4996    –0.1524		8.98398  –0.08636		8.52678		8.6614  +0.2032		9.00938  +0.11176		9.525
							3		0.79375		9.525     –0.1524		9.00938   –0.0635		8.55218		8.6614 +0.14986		9.00938  +0.08382		9.525
	34		7/16—14		UNC		1		1.814286		11.07694  –0.3937		9.89838  –0.18034		8.8519		9.144   +0.4064		9.93394  +0.23368		11.1125
							2		1.814286		11.07694 –0.26162		9.89838  –0.11938		8.8519		9.144   +0.4064		9.93394  +0.15494		11.1125
							3		1.814286		11.1125  –0.26162		9.93394   –0.0889		8.88746		9.144  +0.29718		9.93394  +0.11684		11.1125
	35		7/16—16		UN		2		1.5875		11.07694 –0.23876		10.0457  –0.11684		9.12876		9.398   +0.3556		10.08126 +0.14986		11.1125
							3		1.5875		11.1125  –0.23876		10.08126 –0.08636		9.16432		9.398    +0.254		10.08126  +0.1143		11.1125
序号		规格代号		系列代号		等级		螺距		外螺纹						内螺纹
		名义直径  每英寸牙数								外径		中径		内径		小径		中径		大径
36		7/16—20		UNF		1		1.27		11.07948 –0.30988		10.25398 –0.16002		9.52246		9.7282  +0.3048		10.287   +0.20574		11.1125
						2		1.27		11.07948 –0.20574		10.25398 –0.10668		9.52246		9.7282  +0.3048		10.287   +0.13716		11.1125
						3		1.27		11.1125  –0.20574		10.287   –0.07874		9.55548		9.7282 +0.21844		10.287   +0.10414		11.1125
37		7/16—28		UNEF		2		0.907143		11.08456  –0.1651		10.49528 –0.09144		9.97204		10.1346 +0.2032		10.52322 +0.11684		11.1125
						3		0.907143		11.1125   –0.1651		10.52322 –0.06858		9.99998		10.1346 +0.1549		10.52322 +0.0889		11.1125
38		7/16—32		UN		2		0.79375		11.0871   –0.1524		10.57148 –0.08636		10.11248		10.2616 +0.1778		10.59688 +0.11176		11.1125
						3		0.79375		11.1125   –0.1524		10.59688  –0.0635		10.13968		10.2616 +0.1372		10.59688 +0.08382		11.1125
39		1/2—13		UNC		1		1.953846		12.6619  –0.41402		11.3919  –0.18796		10.26414		10.5918 +0.4318		11.43    +0.24638		12.7
						2		1.953846		12.6619  –0.27686		11.3919    –0.127		10.26414		10.5918 +0.4318		11.43     +0.1651		12.7
						3		1.953846		12.700   –0.27686		11.43    –0.09398		10.30224		10.5918 +0.2896		11.43    +0.12192		12.7
40		01/2—16		UN		2		1.5875		12.66444 –0.23876		11.6332  –0.11938		10.71626		10.9728 +0.3556		11.66876 +0.15494		12.7
						3		1.5875		12.700   –0.23876		11.66876  –0.0889		10.75182		10.9728 +0.2515		11.66876 +0.11684		12.7
41		1/2—20		UNF		1		1.27		12.66698 –0.30988		11.84148 –0.16256		11.10996		11.3284 +0.4318		11.8745  +0.21336		12.7
						2		1.27		12.66698 –0.20574		11.84148 –0.10922		11.10996		11.3284 +0.4318		11.8745  +0.14224		12.7
						3		1.27		12.700   –0.20574		11.8745  –0.08128		11.14298		11.3284 +0.1956		11.8745  +0.10668		12.7
42		1/2—28		UNEF		2		0.907143		12.67206  –0.1651		12.08278 –0.09398		11.55954		11.7094 +0.2286		12.11072 +0.12192		12.7
						3		0.907143		12.700    –0.1651		12.11072 –0.07112		11.58748		11.7094 +0.1676		12.11072 +0.09144		12.7
43		1/2—32		UN		2		0.79375		12.6746   –0.1524		12.15898  –0.0889		11.70178		11.8364 +0.2032		12.18438  +0.1143		12.7
						3		0.79375		12.700    –0.1524		12.18438 –0.06604		11.72718		11.8364 +0.1498		12.18438 +0.08636		12.7
44		9/16—12		UNC		1		2.116667		14.24686 –0.43688		12.87272 –0.19812		11.65098		11.9888 +0.4572		12.91336 +0.25908		14.2875
						2		2.116667		14.24686 –0.28956		12.87272 –0.13208		11.65098		11.9888 +0.4572		12.91336 +0.17272		14.2875
						3		2.116667		14.2875  –0.28956		12.91336 –0.09906		11.70178		11.9888 +0.3124		12.91336 +0.12954		14.2875
45		9/16—16		UN		2		1.5875		14.25194 –0.23876		13.2207  –0.11938		12.30376		12.573  +0.3556		13.25626 +0.15494		14.2875
						3		1.5875		14.2875  –0.23876		13.25626  –0.0889		12.33932		12.573  +0.2286		13.25626 +0.11684		14.2875

 

序号	规格代号	系列代号	等级	螺距	外螺纹			内螺纹
	名义直径  每英寸牙数				外径	中径	内径	小径	中径	大径
46	9/16—18	UNF	1	1.41111	14.25194  –0.33274	13.335     –0.17272	12.51966	12.7508 +0.3302	13.37056 +0.22606	14.2875
			2	1.41111	14.25194  –0.22098	13.335      –0.1143	12.51966	12.7508 +0.3302	13.37056 +0.14986	14.2875
			3	1.41111	14.2875   –0.22098	13.37056    –0.8636	12.55522	12.7508 +0.2184	13.37056 +0.11176	14.2875
47	9/16—20	UN	2	1.27	14.25448  –0.20574	13.42898   –0.10668	12.69746	12.9032 +0.3048	13.462    +0.1397	14.2875
			3	1.27	14.2875   –0.20574	13.462     –0.08128	12.73048	12.9032 +0.2083	13.462   +0.10414	14.2875
48	9/16—24	UNEF	2	1.05833	14.25702  –0.18288	13.56868   –0.09906	12.95908	13.1318 +0.254	13.59916 +0.12954	14.2875
			3	1.05833	1402875  –0.18288	13.59916   –0.07366	12.98956	13.1318 +0.1879	13.59916 +0.09652	14.2875
49	9/16—28	UN	2	0.90714	14.25956   –0.1651	13.67028   –0.09398	13.14704	13.3096 +0.2032	13.69822 +0.11684	14.2875
			3	0.90714	14.2875    –0.1651	13.69822   –0.07112	13.17498	13.3096 +0.1549	13.69822 +0.09144	14.2875
50	9/16—32	UN	2	0.79375	14.2621    –0.1524	13.74648    –0.0889	13.28928	13.4366 +0.1778	13.77188  +0.1143	14.2875
			3	0.79375	14.2875    –0.1524	13.77188   –0.06604	13.31468	13.4366 +0.1372	13.77188 +0.08636	14.2875
51	5/8—11	UNC	1	2.30909	15.83436  –0.46228	14.33576   –0.21082	13.00226	13.3858 +0.4826	14.3764  +0.27178	15.875
			2	2.30909	15.83436  –0.30734	14.33576    –0.1397	13.00226	13.3858 +0.4826	14.3764  +0.18288	15.875
			3	2.30909	15.875    –0.30734	14.3764    –0.10414	13.0429	13.3858 +0.3073	14.3764  +0.13716	15.875
52	5/8—12	UN	2	2.116667	15.83436  –0.28956	14.46022   –0.13716	12.98448	13.589  +0.4572	14.50086 +0.18034	15.875
			3	2.116667	15.875    –0.28956	14.50086   –0.10414	13.27912	13.589 +0.28702	14.50086 +0.13462	15.875
53	5/8—16	UN	2	1.5875	15.83944  –0.23876	14.8082    –0.12192	13.89126	14.1478 +0.3556	14.84376 +0.15748	15.875
			3	1.5875	15.875    –0.23876	14.84376   –0.09144	13.92682	14.1478 +0.2337	14.84376 +0.11684	15.875
54	5/8—18	UNF	1	1.411111	15.83944  –0.33274	14.9225     –0.1778	14.10716	14.351  +0.3302	14.95806 +0.23114	15.875
			2	1.411111	15.83944  –0.22098	14.9225    –0.11938	14.10716	14.351  +0.3302	14.95806  +0.1524	15.875
			3	1.411111	15.875    –0.22098	14.95806    –0.0889	14.14272	14.351  +0.2032	14.95806  +0.1143	15.875
55	5/8—20	UN	2	1.27	15.84198  –0.20574	15.01648   –0.10922	14.28496	14.5034 +0.2794	15.0495  +0.14224	15.875
			3	1.27	15.875    –0.20574	15.0495    –0.08128	14.31798	14.5034 +0.1956	15.0495  +0.10668	15.875
56	5/8—24	UNEF	2	1.05833	15.84452  –0.18288	15.15618    –0.1016	14.54658	14.732   +0.254	15.18666 +0.13208	15.875
			3	1.05833	15.875    –0.18288	15.18666    –0.0762	14.57706	14.732 +0.17526	15.18666 +0.09906	15.875

 

 

序号	规格代号	系列代号	等级	螺距	外螺纹			内螺纹
	名义直径  每英寸牙数				外径	中径	内径	小径	中径	大径
57	5/8—28	UN	2	0.907143	15.84706  –0.1651	15.25778 –0.09652	14.73454	14.8844 +0.2286	15.28572 +0.12446	15.875
			3	0.907143	15.875    –0.1651	15.28572 –0.07112	14.76248	14.8844 +0.1676	15.28572 +0.09398	15.875
58	5/8—32	UN	2	0.79375	15.84706  –0.1524	15.33144 –0.09144	14.87424	15.0114 +0.2032	15.35938 +0.11684	15.875
			3	0.79375	15.875    –0.1524	15.35938 –0.06858	14.90218	15.0114 +0.1499	15.35938  +0.0889	15.875
59	11/16—12	UN	2	2.11667	17.42186 –0.28956	16.04772 –0.13716	14.82598	15.1638 +0.4572	16.08836 +0.18034	17.4625
			3	2.11667	17.4625  –0.28956	16.08836 –0.10414	14.86662	15.1638 +0.2921	16.08836 +0.13462	17.4625
60	11/16—16	UN	2	1.5875	17.42694 –0.23876	16.3957  –0.12192	15.47876	15.748  +0.3556	16.43126 +0.15748	17.4625
			3	1.5875	17.4625  –0.23876	16.43126 –0.09144	15.51432	15.748 +0.21336	16.43126 +0.11684	17.4625
61	11/16—20	UN	2	1.27	17.42948 –0.20574	16.60398 –0.1092	15.87246	16.0782 +0.3048	16.637   +0.14224	17.4625
			3	1.27	17.4625  –0.20574	16.637   –0.08128	15.90548	16.0782 +0.2083	16.637   +0.10668	17.4625
62	11/16—24	UNEF	2	1.058333	17.43202 –0.18288	16.74368  –0.1016	16.13408	16.3068 +0.254	16.77416 +0.13208	17.4625
			3	1.058333	17.4625  –0.18288	16.77416  –0.0762	16.16456	16.3068 +0.1880	16.77416 +0.09906	17.4625
63	11/16—28	UN	2	0.907143	17.43456  –0.1651	16.84528 –0.09652	16.32204	16.4846 +0.2032	16.87322 +0.12466	17.4625
			3	0.907143	17.4625   –0.1651	16.87322 –0.07112	16.34998	16.4846 +0.1549	16.87322 +0.09398	17.4625
64	11/16—32	UN	2	0.79375	17.43456  –0.1524	16.91894 –0.09144	16.46174	16.6116 +0.1778	16.94688 +0.11684	17.4625
			3	0.79375	17.4625   –0.1524	16.94688 –0.06858	16.48968	16.6116 +0.1372	16.94688  +0.0889	17.4625
65	3/4—10	UNC	1	2.54	19.00428 –0.49276	17.35328 –0.22352	15.8877	16.3068 +0.5334	17.399    +0.2921	19.05
			2	2.54	19.00428 –0.32766	17.35328 –0.14986	15.8877	16.3068 +0.5334	17.399   +0.19558	19.05
			3	2.54	19.05    –0.32766	17.399   –0.11176	15.93342	16.3068 +0.3175	17.399   +0.14478	19.05
66	3/4—12	UN	2	2.116667	19.00682 –0.28956	17.63268  –0.1397	16.41094	16.764  +0.4572	17.67586 +0.18288	19.05
			3	2.116667	19.05    –0.28956	17.67586 –0.10414	16.45412	16.764 +0.27178	17.67586 +0.13716	19.05
67	3/4—16	UNF	1	1.5875	19.0119  –0.36068	17.98066  –0.1905	17.06372	17.3228 +0.3556	18.01876 +0.24892	19.05
			2	1.5875	19.0119  –0.23876	17.98066   –0.127	17.06372	17.3228 +0.3556	18.01876  +0.1651	19.05
			3	1.5875	19.05    –0.23876	18.01876 –0.09652	17.10182	17.3228 +0.2235	18.01876 +0.12446	19.05
68	3/4—20	UNEF	2	1.27	19.01698 –0.20574	18.19148 –0.11176	17.45996	17.6784 +0.2794	18.2245  +0.14478	19.05
			3	1.27	19.05    –0.20574	18.2245  –0.08382	17.49298	17.6784 +0.1956	18.2245  +0.10922	19.05

 

 

序号	规格代号	系列代号	等级	螺距	外螺纹			内螺纹
	名义直径  每英寸牙数				外径	中径	内径	小径	中径	大径
69	3/4—28	UN	2	0.907143	19.0195   –0.1651	18.43024 –0.09652	17.907	18.0594 +0.2286	18.46072 +0.127	19.05
			3	0.907143	19.05     –0.1651	18.46072 –0.07366	17.93748	18.0594 +0.1676	18.46072 +0.09398	19.05
70	3/4—32	UN	2	0.79375	19.02206  –0.1524	18.50644 –0.09144	18.04924	18.1864 +0.2032	18.53438 +0.11938	19.05
			3	0.79375	19.05     –0.1524	18.53438 –0.06858	18.07718	18.1864 +0.1499	18.53438 +0.09144	19.05
71	13/16—12	UN	2	2.116667	20.59432 –0.28956	19.22018  –0.1397	17.99844	18.3388 +0.4572	19.26336 +0.18288	20.6375
			3	2.116667	20.6375  –0.28956	19.26336 –0.10414	18.04162	18.3388 +0.2769	19.26336 +0.13716	20.6375
72	13/16—16	UN	2	1.5875	20.5994  –0.23876	19.56816 –0.12446	18.65122	18.923  +0.3556	19.60626 +0.16002	20.6375
			3	1.5875	20.6375  –0.23876	19.60626 –0.09144	18.68932	18.923 +0.21082	19.60626 +0.11938	20.6375
73	13/16—20	UNEF	2	1.27	20.60448 –0.20574	19.77898 –0.11176	19.04746	19.2532 +0.3048	19.812   +0.14478	20.6375
			3	1.27	20.6375  –0.20574	19.812    –0.8382	19.08048	19.2532 +0.2083	19.812   +0.10922	20.6375
74	13/16—28	UN	2	0.907143	20.607    –0.1651	20.01774 –0.09652	19.4945	19.6596 +0.2032	20.04822   +0.127	20.6375
			3	0.907143	20.6375   –0.1651	20.04822 –0.07366	19.52498	19.6596 +0.1549	20.04822 +0.09398	20.6375
75	13/16—32	UN	2	0.79375	20.60956  –0.1524	20.09394 –0.09144	19.63674	19.7866 +0.1778	20.12188 +0.11938	20.6375
			3	0.79375	20.6375   –0.1524	20.12188 –0.06858	19.66468	19.7866 +0.1372	20.12188 +0.09144	20.6375
76	7/8—9	UNC	1	2.822222	22.17674 –0.52832	20.34286  –0.2413	18.71472	19.177 +0.5842	20.39112 +0.31242	22.225
			2	2.822222	22.17674 –0.35306	20.34286 –0.16002	18.71472	19.177 +0.5842	20.39112 +0.20828	22.225
			3	2.822222	22.225   –0.35306	20.39112 –0.11938	18.76298	19.177 +0.33274	20.39112 +0.15494	22.225
77	7/8—12	UN	2	2.116667	22.18182 –0.28956	20.80768  –0.1397	19.58594	19.939  +0.4572	20.85086 +0.18288	22.225
			3	2.116667	22.225   –0.28956	20.85086 –0.10414	19.62912	19.939 +0.25908	20.85086 +0.13716	22.225
78	7/8—14	UNF	1	1.814286	22.18436  –0.3937	21.0058  –0.20574	19.95932	20.2692 +0.4064	21.04644 +0.26924	22.225
			2	1.814286	22.18436 –0.26162	21.0058  –0.13716	19.95932	20.2692 +0.4064	21.04644  +0.1778	22.225
			3	1.814286	22.225   –0.26162	21.04644 –0.10414	19.99996	20.2692 +0.2235	21.04644 +0.13462	22.225
79	7/8—16	UN	2	1.5875	22.1869  –0.23876	21.15566 –0.12446	20.23872	20.4978 +0.3556	21.19376 +0.16002	22.225
			3	1.5875	22.225   –0.23876	21.19376 –0.09144	20.27682	20.4978 +0.2235	21.19376 +0.11938	22.225
80	7/8—20	UNEF	2	1.27	22.19198 –0.20574	21.36648 –0.11176	20.63496	20.8534 +0.2794	21.3995  +0.14478	22.225
			3	1.27	22.225   –0.20574	21.3995  –0.08382	20.66798	20.8534 +0.1956	21.3995  +0.10922	22.225

 

 

 

准备攻丝的螺纹	钻头规格代码	(最接近的英制分数规格)	英制小数规格	公制尺寸
1/8"-27NPT	字母R	-	.3390	Ø8.61
1/4"-18NPT	7/16"	7/16"	.4375	Ø11.11
3/8"-18NPT	14.68	37/64"	.5781	Ø14.68
1/2"-14NPT	45/64"	45/64"	.7031	Ø17.85
3/4"-14NPT	59/64"	59/64"	.9219	Ø23.41
1"-11½ NPT	15/32"	15/32"	1.1562	Ø29.37
1¼"-11 ½ NPT	1½"	1½"	1.5000	Ø38.1
1½"-11 ½ NPT	147/64"	147/64"	1.7344	Ø44.05
2"-11½ NPT	27/32"	27/32"	2.2188	Ø56.35

  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

牙形高度=D-d除2。这是单边量。

d的算法有很多种，根据不同的罗纹有不同的值。下面我给你具体分开来算：

1：公制螺纹d=D-1.0825乘P；

2：55度英制螺纹d=D-1.2乘P；

3：60度圆锥管螺纹d=D-1.6乘P；

4：55度圆锥管螺纹d=D-1.28乘P；

5：55度圆柱管螺纹d=D-1.3乘P；

6：60度米制锥螺纹d=D-1.3乘P；

注：d=螺纹小径，D=螺纹大径，P=螺距，H就是牙形高度

粗牙就是M+公称直径（也就是螺纹大径）。例如：M10，M16

细牙就是M+公称直径乘螺距。例如：M10X1，M20X1.5

当螺纹为左旋时，会标注“左”，右旋时不标注。

还有一种标注法：例如，M10——5g6g（这就是外螺纹），M10——6H（这就是内螺纹）

注:内外螺纹都是大径算小径.公式一样

 

 

英寸制统一螺纹，在英寸制国家广泛采用，该类螺纹分三个系列：粗牙系列UNC，细牙系列UNF，特细牙系列UNFF，外加一个定螺距系列UN。

标注方法：螺纹直径—每英寸牙数 系列代号—精度等级

示例：粗牙系列 3/8—16 UNC—2A

细牙系列 3/8—24 UNF—2A

特细牙系列 3/8—32 UNFF—2A

定螺距系列 3/8—20 UN—2A

第一位数字3/8表示螺纹外径，单位为英寸，转换为米制单位mm要乘以25.4，即3/8×25.4=9.525mm；第二、三位数字16、24、32、20为每英寸牙数(在25.4mm长度上的牙数)；第三位以后的文字代号UNC、UNF、UNFF、UN为系列代号，最后两位2A为精度等级。

螺纹配合等级：

三、螺纹配合是旋合螺纹之间松或紧的大小，配合的等级是作用在内外螺纹上偏差和公差的规定组合。

（一）、对统一英制螺纹，外螺纹有三种螺纹等级：1A、2A和3A级，内螺纹有三种等级：

1B、2B和3B级，全部都是间隙配合。等级数字越高，配合越紧。在英制螺纹中，偏差仅规定1A和2A级，3A级的偏差为零，而且1A和2A级的等级偏差是相等的。

 

1、1A和1B级，非常松的公差等级，其适用于内外螺纹的允差配合。

2、2A和2B级，是英制系列机械紧固件规定最通用的螺纹公差等级。

3、3A和3B级，旋合形成最紧的配合，适用于公差紧的紧固件，用于安全性的关键设计。

4、对外螺纹来说，1A和2A级有一个配合公差，3A级没有。1A级公差比2A级公差大50%，比3A级大75%，对内螺纹来说，2B级公差比2A公差大30%。1B级比2B级大50%，比3B级大75%。