STREWM, HOLT*, aSD KITO 



*quare thread. In the caaeor the triangular 

 thread there ia alao a tendency of the preavur* to l.u> 



Huttr*** thremi shown at (*) U deaigned to combine 

 the advantage* of the V ami square threada, but it only haa 

 thaw advantagea when the preature U transmitted in one 

 direct! .* pressure be reveraed t the 



> uixl l.urstmg action on the nut are even greater than 

 with tin- V thread, becauae of the greatrr ,,f the 



slant httle of the buttress thread. The anglea of the square 

 thread are frequently rounded to a greater or leta extent to 

 render them leaa eaaily damaged. 



exceat we get the KnuckU thread ahown und- 



ing of the anglea increase* both the strength a- .1 th<- fn 



rm of Screw Tkr, tw to a scale of 



three times roll sice the sections of screw threads as shown in 

 fig. 9. Whit , .rth. Sellers, and buttrses threads 



to be | incli. and the jut-h >f the square and knuckle threads to be 



;:. 



40 



n 



M 



IS 



II 



9 

 8 



7 



' ol 



on 



186 



IN 



346 



,...; 



m 



^ 



crtw ~,~ h <rfthrmd 





H 



-' 





: Oil 



: m 



i M 



! .- 



X 384 



. ' ! 



; 



; 



. 



HI 

 4 7S ! 



; , 



( ll'A.-f T,.rf A 



Number of threads 

 nerioeh . .'M,I9 19 



14 M II 11 11 II 11 11 



i , ., . ' . - - 



