Page:Practical Treatise on Milling and Milling Machines.djvu/216

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INDEX TABLE 2 to 50

Plain & Differential Indexing

Number of Divisions	Index Circle	No of Turns of Index	Graduation
2	Any	20
3	39	13 13/39	65
	33	13 11/33	65
	18	13 6/18	65
4	Any	10
5	Any	8
6	39	6 26/39	132
	33	6 26/33	132
	18	6 12/18	132
7	49	5 35/49	140
	21	5 13/21	142
8	Any	5
9	27	4 12/27	88
	19	8/18	87
10	Any	4
11	33	3 21/33	126
12	39	3 13/39	65
	33	3 11/33	65
	18	3 6/18	65
13	39	3 63/39	14
14	49	2 42/49	169
	21	2 18/21	170
15	39	2 26/39	132
	33	2 22/33	132
	18	2 12/18	132
16	20	2 10/20	98
17	17	2 6/17	69
18	27	2 6/27	43
	18	2 4/18	43
19	19	2 2/19	43
20	Any	2
21	21	1 19/21	18*
22	33	1 27/33	161
23	23	1 17/23	147
24	39	1 26/39	132
	33	1 22/33	132
	18	1 12/18	132
25	20	1 12/20	118
26	39	1 21/39	106
27	27	1 13/27	95
28	49	1 21/49	83
	21	1 9/21	83
29	29	1 11/29	75
30	39	1 13/39	65
	33	1 11/33	65
	18	1 6/18	65
31	31	1 9/31	56
32	20	1 5/20	48
33	33	1 7/33	41
34	17	1 3/17	33
35	49	1 7/49	26
	21	1 3/21	28
36	27	1 3/27	21
	18	1 2/18	21
37	37	1 3/37	15
38	19	1 1/19	9
39	39	1 1/39	3
40	Any	1
41	41	40/41	3*
42	21	20/21	9*
43	43	40/43	12*
44	33	30/33	17*
45	27	24/27	21*
	18	16/18	21*
46	23	20/23	172
47	47	40/47	168
48	18	15/18	165
49	49	40/49	161
50	20	16/20	158
GRADUATION IN TABLE INDICATE SETTING FOR ARMS SECTOR WHEN INDEX MOVES THROUGH CRANK INDICATE "A," ARMS WHEN EXCEPT CASES MARKED * WHEN THE INDEX CRANK MOVES THROUGH ARC "B."