Page:Practical Treatise on Milling and Milling Machines.djvu/332

---

TABLE FOR OBTAINING SET-OVER FOR CUTTING BEVEL GEARS

RATIO OF APEX DISTANCE TO WIDTH OF FACE =⁠APEX/FACE⁠

No. of Cutter	3 1	3+3⁄4 1	3+1⁄2 1	3+3⁄4 1	4 1	4+1⁄4 1	4+1⁄2 1	4+3⁄4 1	5 1	5+1⁄2 1	6 1	7 1	8 1
1	.254	.254	.255	.256	.257	.257	.257	.258	.258	.259	.260	.262	.264
2	.266	.268	.271	.272	.273	.274	.274	.275	.277	.279	.280	.283	.284
3	.266	.268	.271	.273	.275	.278	.280	.282	.283	.286	.287	.290	.292
4	.275	.280	.285	.287	.291	.293	.296	.298	.298	.302	.305	.308	.311
5	.280	.285	.290	.293	.295	.296	.298	.300	.302	.307	.309	.313	.315
6	.311	.318	.323	.328	.330	.334	.337	.340	.343	.348	.352	.356	.362
7	.289	.298	.308	.316	.324	.329	.334	.338	.343	.350	.360	.370	.376
8	.275	.286	.296	.309	.319	.331	.338	.344	.352	.361	.368	.380	.386

TABLE OF CUTTERS, PITCHES, GEARS AND ANGLES FOR TWIST DRILLS

Diameter of Drill	Thickness of cutter	Pitch in Inches	Gear on Worm	First Gear on Stud	Second Gear on Stud	Gear on Screw	Angle of Spiral
⁠1/16⁠	.06	.67	24	86	24	100	16° 20′
⁠1/8⁠	.08	1.12	24	86	40	100	19° 20’
⁠3/16⁠	.11	1.67	24	64	32	72	19° 25′
⁠1/4⁠	.15	1.94	32	64	28	72	21° 00
⁠5/16⁠	.19	2.92	24	64	56	72	20° 00
⁠3/8⁠	.23	3.24	40	48	28	72	21° 00
⁠7/16⁠	.27	3.89	56	48	24	72	20° 10′
⁠1/2⁠	.31	4.17	40	72	48	64	20° 30′
⁠9/16⁠	.35	4.86	40	64	56	72	20° 00
⁠5/8⁠	.39	5.33	48	40	32	72	20° 12′
⁠11/16⁠	.44	6.12	56	40	28	64	19° 30′
⁠3/4⁠	.50	6.48	56	48	40	72	20° ((phantom|00}}
⁠13/16⁠	.56	7.29	56	48	32	56	19° 20′
⁠7/8⁠	.62	7.62	64	48	32	56	19° 50′
⁠15/16⁠	.70	8.33	48	32	40	72	19° 30′
1	.77	8.95	86	48	28	56	19° 20′
⁠1+1/8⁠	.85	9.33	56	40	48	72	20° 40′