Steel Pipes/Plain/Metric Thread

 

(1) Thread Nominal	Thread				Gauge Dia.			Position of Gauge Dia.			Tolerance of Parallel Female Thread D, D2, and D1	Effective Thread Length (Min.)				Dimensions of Carbon Steel Pipe (Reference)
	Number of Threads in 25.4mm n	Pitch P (Reference)	Height of Threads h	Roundness r or r′	Male Thread			Male Thread		Female Thread		Male Thread	Female Thread
												From Position of Gauge Dia. to Large Dia. Side f	With Imperfect Thread Portion		W/O Imperfect Thread Portion
								From Pipe End		Pipe End
					O.D. d	Effective Dia. d2	Root Dia. d1						Tapered Female Threads	Parallel Female Threads	Tapered Female Threads , Parallel Female Threads
								Reference Length a	Tolerance in Direction of axis b	Tolerance in Direction of axis c
					Female Thread								From Position of Gauge Dia. to Small Dia. Side ℓ	From Pipe End or Pipe Joint End ℓ′ (Reference)	t（2）	O.D.	Thickness
					Root Dia. D	Effective Dia. D2	I.D. D1
R1/16	28	0.9071	0.581	0.12	7.723	7.142	6.561	3.97	±0.91	±1.13	±0.071	2.5	6.2	7.4	4.4	－	－
R1/8	28	0.9071	0.581	0.12	9.728	9.147	8.566	3.97	±0.91	±1.13	±0.071	2.5	6.2	7.4	4.4	10.5	2.0
R1/4	19	1.3368	0.856	0.18	13.157	12.301	11.445	6.01	±1.34	±1.67	±0.104	3.7	9.4	11.0	6.7	13.8	2.3
R3/8	19	1.3368	0.856	0.18	16.662	15.806	14.950	6.35	±1.34	±1.67	±0.104	3.7	9.7	11.4	7.0	17.3	2.3
R1/2	14	1.8143	1.162	0.25	20.955	19.793	18.631	8.16	±1.81	±2.27	±0.142	5.0	12.7	15.0	9.1	21.7	2.8
R3/4	14	1.8143	1.162	0.25	26.441	25.279	24.117	9.53	±1.81	±2.27	±0.142	5.0	14.1	16.3	10.2	27.2	2.8
R1	11	2.3091	1.479	0.32	33.249	31.770	30.291	10.39	±2.31	±2.89	±0.181	6.4	16.2	19.1	11.6	34	3.2
R11/4	11	2.3091	1.479	0.32	41.910	40.431	38.952	12.70	±2.31	±2.89	±0.181	6.4	18.5	21.4	13.4	42.7	3.5
R11/2	11	2.3091	1.479	0.32	47.803	46.324	44.845	12.70	±2.31	±2.89	±0.181	6.4	18.5	21.4	13.4	48.6	3.5
R2	11	2.3091	1.479	0.32	59.614	58.135	56.656	15.88	±2.31	±2.89	±0.181	7.5	22.8	25.7	16.9	60.5	3.8
R21/2	11	2.3091	1.479	0.32	75.184	73.705	72.226	17.46	±3.46	±3.46	±0.216	9.2	26.7	30.1	18.6	76.3	4.2
R3	11	2.3091	1.479	0.32	87.884	86.405	84.926	20.64	±3.46	±3.46	±0.216	9.2	29.8	33.3	21.1	89.1	4.2
R4	11	2.3091	1.479	0.32	113.030	111.551	110.072	25.40	±3.46	±3.46	±0.216	10.4	35.8	39.3	25.9	114.3	4.5
R5	11	2.3091	1.479	0.32	138.430	136.951	135.472	28.58	±3.46	±3.46	±0.216	11.5	40.1	43.5	29.3	139.8	4.5
R6	11	2.3091	1.479	0.32	163.830	162.351	160.872	28.58	±3.46	±3.46	±0.216	11.5	40.1	43.5	29.3	165.2	5.0

Notes (1): This nominal is for tapered male threads. For tapered and parallel female threads, the symbol for R is Rc or Rp (* Reference).
(2): Taper threads are the length from the position of gauge dia. to the small diameter side, and parallel female threads are the length from the pipe or
   pipe joint end.
Remarks: 1. The threads are perpendicular to the central axis line and the pitch is measured along the central axis line.
2. The effective thread length is the length of the fully threaded thread, only the last few threads of which may be allowed to have a pipe or
pipe joint face remaining at the top.
Even if the pipe or pipe joint end is chamfered, this portion is included in the effective thread length.
3. If the value is not close to the value in this table, it shall be in accordance with the standards for parts specified separately.
(*) The types of tapered threads for pipes include tapered male threads, tapered female threads, and parallel female threads.
This parallel female threads are used with tapered male threads, and the dimension tolerances differ from those of the parallel female threads specified in JIS B 0202.