Pocketbook of Useful Formulæ and Memoranda
for Civil and Mechanical Engineers

400 MOLESWORTH S POCKET-BOOK Rules for the Diameter and Pitch of Toothed . AVi HEELS. P = Diameter of pitch circle. N — Number of teeth. P = Pitch ot teeth calculated as measured round the pitch circle. tt = 3*41519; TT P. N D For values of æ, yt and z, seethe following tables. 0 13-14169 l-57080i 1-04720 , -78540 I -62832 <52360 25’1327 1 I 2’79203 ! >1-47840 >1-00631 > -76160 ! -61299 ) -51291 •31831 •63662 .•95493 1-27324 1-59155, 1-909861 PitoJ). 12*5664 8*37708 6*28319 5-026Ö5 4-18879 3-^080 2-51327 2'28479 2--------— • —. , 1-39626 1-32278 : •96664 ‘ ~ •73920 •69840 •60266 •93084 •71808 •58448 •49280 2-09440 1-25664 •89760 •69813 •67l2‘i •48332 1*93329 1-795201 67552 1-19680 1-14240J1 *09273 '86665 '83776 *81073 •67926 *66139 ’64443 •67926 ________ . T_.ia| •66851 -64636 '53474 •47420 *46542' -4S696 2 3 6 6 •125 •25 •375 •6 •625 •75 •876 Pitch. 8 •08979 •35810 •67641 •99472 ■1-31303 .1-68134 ! 1-94965 Values of y. 7. J Pitch. •278521 •59683' •91514! ill-23345' ’ 1 5517B 1-98944 2-02923 2’06901 2-10880 2 14859 2*18838' . .5 -625 I ’75 1 -875 Pitch. ■19894 •51725 •83.^56 •15887 • 079581 *11937 *15915 '39789 -43768 -47746 ■71620 -75599 ’79577 1-03451 1-07430 1*11408 1 85282 I*39261 1-43239 1-47218 1-67113 1-71Ö92 1-75070 1 *79049 •125 I *25 I *375 •23873 •55704 •87.535 1-193661’ 1-61197! 1*83028 : 2 3 6 6