Thread Roll Blank Preparation

Machine Diameters, Chamfer Diameters, Minimum Relief Width & Chamfer angles

Size  Machine  Chamfer 
Thread Dia. Dia.
     
.1120-40 .100/.105 .072
     
.1380-32 .122/.127 .085
     
.1380-40 .125/.130 .090
     
.1640-32 .142/.153 .112
     
.1900-32 .172/.177 .140
     
.2500-20 .223/.228 .168
     
.2500-28 .230/.235 .187
     
.3125-18 .280/.285 .220
     
.3125-24 .290/.295 .240
     
.3750-16 .339/.344 .272
     
.3750-24 .352/.357 .305
     
.4375-20 .410/.415 .350
     
.5000-13 .455/.460 .375
     
.5000-20 .470/.475 .415
     
.5625-18 .530/.535 .470
     
.6250-11 .570/.575 .480
     
.6250-18 .592/.597 .530
     
.7500-10 .690/.695 .595
     
.7500-16 .712/.717 .645
     
.8750-14 .831/.836 .755
     
1.000-12 .950/.955 .870
     
1.000-14 .958/.963 .880
     
1.125-12 1.075/1.081 .990
     
     

 

 

 

 

 

    Sizes given are adequate for both UNF & UNJF class 3A & 2A. Blanks will be centerless or cylindrical ground and thread rolled to you specifications.

 

                                           Rolled Threads - General information

bullet Thread sizes not listed:

        A.    Machine diameter to be .005/.010" above maximum pitch diameter to be rolled.

        B.    Chamfer diameter to be minor diameter less one/half of a thread pitch.

bullet Minimum complete threads or perfect thread length callouts, should be turned one and three fourths to two thread pitches in length beyond complete thread length specified.                                                         
bullet Material that is heat-treated above 150,000 KSI before thread rolling has a direct effect on roll die life. Contact your thread roll source before proceeding.
bullet Acceptable 45 degree chamfers will result from a 30 degree lead angle in most cases. However, very close tolerance relief and lead angles may have to be machined after thread roll.
bullet To insure consistent quality therad rolling, turned blank length should be held within + .005".

 

                J.D.OTT COMPANY, INC.

                 2244 6th Avenue South     Seattle Wa. 98134      Tel. (206) 749-0777