G-SERIES PIPE THREAD (BRITISH
STANDARD PIPE PARALLEL was BSPP & BSPF)
PF-SERIES PIPE THREAD (JAPANESE PIPE PARALLEL)

 

British Pipe Thread ( Whitworth Form) — Parallel (BSPP/BSPF)
Thread Designation	Nominal Size	Thread Form Type	Major Diameter mm d=D	Pitch mm p	Threads per inch	Pitch Diameter mm d2=D2	Minor Diameter Male Thd. d3	Thread Height H1	Tap Drill Diameter mm
G1/8	1/8″	BSPP	9.728	0.907	28	9.147	8.566	0.581	8.70
G1/4	1/4″	BSPP	13.157	1.337	19	12.301	11.445	0.856	11.60
G3/8	3/8″	BSPP	16.662	1.337	19	15.806	14.950	0.856	15.00
G1/2	1/2″	BSPP	20.955	1.814	14	19.793	18.631	1.162	19.00
G5/8	5/8″	BSPP	22.911	1.814	14	21.749	20.587	1.162	20.75
G3/4	3/4″	BSPP	26.441	1.814	14	25.279	24.117	1.162	24.50
G7/8	7/8″	BSPP	30.201	1.814	14	29.039	27.877	1.162	28.00
G1	1″	BSPP	33.249	2.309	11	31.770	30.291	1.479	30.50
G1-1/8	1-1/8″	BSPP	37.897	2.309	11	36.418	34.939	1.479	35.00
G1-1/4	1-1/4″	BSPP	41.910	2.309	11	40.431	38.952	1.479	39.50
G1-3/8	1-3/8″	BSPP	44.323	2.309	11	42.844	41.365	1.479	41.50
G1-1/2	1-1/2″	BSPP	47.803	2.309	11	46.324	44.845	1.479	45.00
G1-3/4	1-3/4″	BSPP	53.746	2.309	11	52.267	50.788	1.479	51.00
G2	2″	BSPP	59.614	2.309	11	58.135	56.656	1.479	57.00
G2-1/4	2-1/4″	BSPP	65.71	2.309	11	64.231	62.752	1.479	63.00
G2-1/2	2-1/2″	BSPP	75.184	2.309	11	73.705	72.226	1.479	72.50
G2-3/4	2-3/4″	BSPP	81.534	2.309	11	80.055	78.576	1.479	79.00
3	3″	BSPP	87.884	2.309	11	86.405	84.926	1.479	85.50
G3-1/4	3-1/4″	BSPP	93.98	2.309	11	92.501	91.022	1.479	91.00
G3-1/2	3-1/2″	BSPP	100.33	2.309	11	98.351	97.372	1.479	97.75
G3-3/4	3-3/4″	BSPP	106.68	2.309	11	105.201	103.722	1.479	104.00
G4	4″	BSPP	113.03	2.309	11	111.55	110.072	1.479	110.50
G4-1/2	4-1/2″	BSPP	125.73	2.309	11	124.251	122.772	1.479	123.00
G5	5″	BSPP	138.43	2.309	11	136.951	135.472	1.479	136.00
G5-1/2	5-1/2″	BSPP	151.13	2.309	11	149.651	148.172	1.479	148.50
G6	6″	BSPP	163.83	2.309	11	162.351	160.872	1.479	161.50

Disclaimer