Header Info Line

Diameter, mm	United States/Canada	Europe	UK/Australia	Singapore/Japan	Hong Kong	Switzerland
14.1	3	44	F1/2	4	6	4
14.3		45	G	5		5 1/4
14.5	3.5		G1/2		7
14.7		46	H	6		6 1/2
14.9	4	47	H1/2	7	8
15.1			I			7 3/4
15.3	4.5	48	I1/2	8	9
15.5			J		10	9
15.7	5	49	J1/2	9
15.9		50	K		11	10
16.1	5.5		K1/2	10
16.3		51	L		12	11 3/4
16.5	6	52	L1/2	11	13	12 3/4
16.7			M	12
16.9	6.5	53	M1/2	13	14	14
17.1			N
17.3	7	54	N1/2	14	15	15 3/4
17.5		55	O		16
17.7	7.5		O1/2	15		16 1/2
17.9		56	P		17
18.1	8	57	P1/2	16		17 3/4
18.2
18.3			Q
18.5	8.5	58	Q1/2	17
18.8		59	R		19	19
19	9		R1/2	18	20
19.2		60	S			20 1/4
19.4	9.5	61	S1/2	19	21
19.6			T			21 1/2
19.8	10	62	T1/2	20	22
20			U	21
20.2	10.5	63	U1/2	22	23	22 3/4
20.4		64	V		24
20.6	11		V1/2	23
20.8		65	W		25	25
21	11.5	66	W1/2	24
21.2			X		26
21.4	12	67	X1/2	25	27	27 1/2
21.6			Y
21.8	12.5	68	Z	26		28 3/4
22		69	Z1/2
22.2	13	70		27
22.4		Z+1
22.6	13.5	Z+2