... to1 .299P 299 G 3tol .31 5P .407 G 5tol .31 9P . 434 G Number of Teeth 20 2s 30 .33 3P .35 9P .38 8P .33 3G .35 9G .WG .35 1 P .37 9 P .409 P .428G .444G .462G .35 7 P .38 5P .415P A51 ... 144 133 118 Rules of Thumb for Mechanical Engineers Figure 7. Ratio of specific heat (n-value). 70 65 60 55 50 I- I W c-? = 45 II: 4 -1 2 40 35 -I 0 z 30 25 20 ... 1o.ooo 30 76 11,000 16 406 B 6,000-1 8 ,OW 10.000 -31 ,000 10,000 30 76 7.700 23 584 C 13, ooO -31 .OOO 22,000- 53. 000 10,ooo 30 n 5.900 30 762 D 23, 000-44.000 39 .000-75.000...