164 



HANDBOOK OF MECHANICAL DESIGN 



SHAFT DIAMETERS BASED ON THE A.S.M.E. CODE 



M 3 



—I 

 1 



d 



8 4H 



o 



E 

 o 



"5 



c 

 o 



8- 



10 



12-" 



o 



I 



Bending Moment, in 1,000 In.-Lb. 



to rj- ir> to f^ 



0- 



2- 



3- 



4- 



7- 



10 



14 



15- 



16- 



00 



_] 



20 



6 8 10 12 14 16 18 

 Stafionary Shaft -Gradually Applied Loads 

 Bending Moment, in 1,000 In.-Lb. 



-2 

 -4 

 -6 

 -8 

 -10 

 ■12 

 -14 

 ■16 

 1-18 

 -20 

 -22 

 -24 

 -26 

 -28 

 -30 

 L32 



-5 -4 





 h I 



2 

 |-3 



1-6 

 7 

 8 



1-9 

 10 

 II 

 12 

 13 

 14 



22 24 



-16 

 17 

 18 

 19 



h20 



21 

 22 

 23 

 24 

 25 



•-26 



5 

 1-6 



7 

 8 

 9 



E 

 d. 



o 

 o 



o 



11 



O 



-15 [-12^ 



13 



14 



-15 

 16 



-17 



18 



19 

 20 



Scales (for rotating shafts) : 



A. Gradually applied loads. 



B. Suddenly applied loads, minor shocks. 



C. Suddenly applied loads, heavy shocks. 



D. Severe operating conditions, high rehability. 



Use of the Charts. Example. — Consider a shaft trans- 

 mitting a steady load of 25 hp. at 200 r.p.m. and sub- 

 jected to a bending moment of 10,000 in.-lb. If the 

 shaft is made of ordinary cold-drawn shafting used for 

 power transmission work and has a keyway at the point 

 where the bending moment is maximum, a working stress 

 of 6,000 lb. per sq. in. should be used. To find the 



horsepower at 100 r.p.m., the following formula can 

 be used: 



Hp. at 100 r.p.m. = 



hp. transmitted 



X 100 



r.p.m. of shaft 



For this problem, the horsepower at 100 r.p.m. is 

 12.5. Trace across from 12.5 to 10,000 in.-lb., bending 

 moment line for the scale for steady loads. The shafting 

 size is found to be 2^6 in. If there were no keyways, a 

 working stress of 8,000 lb. per sq. in. could be used. The 

 factor for this stress would be 2^6 X 0.909 = 2.19. 

 Therefore a 2JJi6-in. shaft could be used if there were no 

 keyway present. 



