439 OF ENGINEERING FORMULÆ.
Speed of Cutting Tools.
Speeds for cast iron generally, 150 to 190 inches
per minjate, boring 80 inches per minute.
Speeds for wrought iron, about 260 to 280
inches per minute.
For yellow brass, about 300 inches per minute.
Speed of planers, about 15 feet per minute.
Speed of shapers, about 12 feet per minute.
For drilling, tapping, or boring, the speed of
the circumference of the tool should bo from 80 to
120 inches per minute in cast iron, and from 140
to 160 in wrought iron.
Speeds fob Tubmin« and Bobin® Cast Ikon.
Diam. in Ins. Revolutions per Minute. Diam. in Ins. Eevolutions per Minute.
Turning. Boring. Turning. Boring.
1 50'92 25’46 20 2-54 1-27 •
2 25*46 12’73 25 2-0-1 1'02
3 16-96 8’48 30 1-70 •85
4 12-U 6-37 35 1-46 •73
5 10’20 5-10 40 1’28 •64
6 8’48 4’24 45 1-12 •56
1 7-28 3-64 50 1-02 •51
8 6'36 3-18 60 ■84 •42
9 5-66 2-83 70 •72 •36
10 5-10 2-55 80 •64 •32
12 4-24 2-12 90 •56 •28
15 3-40 1-70 100 •50 •25
Speed for turning chilled rolls .. 3 ft. per min.
„ rifling steel guns .. .. 3f „
, f boring cast guns .. ..4 „
, , rifling bronze guns ..20 ,,
„ screw cutting in steel. • 7| „
„ drilling steel small arms 30 „
„ drilling gun-metal ..100 „