TABLE OF APPROXIMATE ANGLES FOR CUTTING SPIRALS
TANGENT OF ANGLE OF SPIRAL= CIRCUMPERENCE OF CUTTER, DRILL, OR MILL
LEAD IN INCHES TO ONE TURN
C-CIRCUMFERENCE OF CUTTER, DRILL, OR MILL
L-LEAD IN INCHES TO ONE TURN
T TANGENT OF ANGLE OF SPIRAL
T=C
L
L=C
T
NOS, OF TEETH IN GEARS FURNISHED WITH MACHINE
24(2) 28 32 40 44 48 56 64 72 80 10o
THE LEAD IN INCHES TO ONE TURN=10 X GEAR ON WORM X 2ND GEAR ON STUD
GEAR ON SCREW X 1ST GEAR ON STUD
EXAMPLE ILLUSTRATING USE OF TABLE DIAMETER OF CUTTER, DRILL, OR MILL 1¼ LEAD IN INCHES TO ONE TURN 3.140 REQUIRED ANGLE TO NEAREST QUARTER DEGREE TO SET SADDLE OF UNIVERSAL MILLING MACHINE 54¼
GEAR ON WORM
1ST GEAR ON STUD
2ND GEAR ON STUD
GEAR ON SCREW
TO ONE TURN
LEAD IN INCHES TO ONE TURN
DIAMETER Or CUTTER, DRILL, OR MILL
| ⅛ | ¼" | ⅜" | ½" | ⅝" | ¾" | ⅞" | 1¼" | 1½" | 1¾" | 2" | 2¼ | 2½" | 2¾" | 3" | 3¼" | 3½" | 3¾" | 4" | 4¼" | 4½" | 4¾" | 5" | 5¼ | "5½ | 5¾" | 6" |
| 24 | 72 | 28 | 86 | 1.08 | 20 | 36 | 47¼ | |||||||||||||||||||
| 24 | 72 | 32 | 86 | 1.240 | 17½ | 32¼ | 43½ | 51¾ | ||||||||||||||||||
| 24 | 72 | 40 | 100 | 1.333 | 16½ | 30½ | 41½ | 49¾ | ||||||||||||||||||
| 24 | 48 | 28 | 100 | 1.400 | 15½ | 29¼ | 40 | 48¼ | ||||||||||||||||||
| 24 | 64 | 40 | 100 | 1.500 | 14¾ | 27¾ | 38¼ | 46¼ | 52¼ | |||||||||||||||||
| 28 | 56 | 32 | 100 | 1.600 | 13¾ | 26¼ | 36¼ | 44½ | 50¾ | |||||||||||||||||
| 24 | 72 | 44 | 86 | 1.706 | 13 | 24¾ | 34½ | 42½ | 49 | |||||||||||||||||
| 24 | 64 | 48 | 100 | 1.800 | 12¼ | 23 | 33¼ | 41 | 47½ | 52½ | ||||||||||||||||
| 24 | 40 | 32 | 100 | 1.920 | 11½ | 22 | 31½ | 39¼ | 45¾ | 50¾ | ||||||||||||||||
| 28 | 64 | 40 | 86 | 2.035 | 11 | 21 | 30 | 37¾ | 44 | 49¼ | ||||||||||||||||
| 24 | 72 | 56 | 86 | 2.171 | 10¾ | 20 | 28½ | 35¾ | 42 | 47¼ | 51¾ | |||||||||||||||
| 24 | 64 | 44 | 72 | 2.292 | 9¾ | 19 | 27¼ | 34½ | 40½ | 45¾ | 50¼ | |||||||||||||||
| 28 | 64 | 56 | 100 | 2.450 | 9 | 17¾ | 25¾ | 32¾ | 38¾ | 44 | 48¼ | 52 | ||||||||||||||
| 40 | 86 | 56 | 100 | 2.605 | 8½ | 16¾ | 24¼ | 31 | 37 | 42 | 46½ | 50¼ | ||||||||||||||
| 40 | 56 | 28 | 72 | 2.778 | 8 | 15¾ | 23 | 29½ | 35¼ | 40¼ | 44¾ | 48½ | ||||||||||||||
| 24 | 56 | 44 | 64 | 2.946 | 7½ | 15 | 21¾ | 28 | 33¾ | 38¾ | 43 | 46¾ | ||||||||||||||
| 24 | 86 | 72 | 64 | 3.140 | 7 | 14 | 20½ | 26½ | 32 | 37 | 41¼ | 45 | 51¼ | <r1> | ||||||||||||
| 28 | 56 | 48 | 72 | 3.333 | 6¾ | 13¼ | 19½ | 25¼ | 30½ | 35¼ | 39½ | 43¼ | 49¾ |
48 44 28 86 3.552 6 12 1823 29 33 3741 4753 44 56 48 100 3.771 72 100 48 86 4.019 5 11 1621 26 301 34 38 44 49 64 48 32 100 4.267 5 10 15 20 24 29 32 36} 42 47 52 56 48 28 72 4.537 5 9 14 19 23 27 3134 41 46 50 56 64 40 72 4.861 4} Fosha, 9 17 25 32 38 44 4852 8 15 23 (29 35 40} 4448 a 7 14 20 26 32 37 4145 51
...........-3.140 6 11 1722 27) 32 36 3946 51 9 1318 22 25 29 32 39 44 48 52!
