By -
Date 03-13-2006 19:42
John,
If I'm working to D1.1, Figures 4.15 to 4.17 say that I can use the "specified or actual base metal yield strength". A572 Gr50 is specified as a 50ksi yield strength material. Usually the actual yield strength is somewhat higher, so if you use 3/4" radius plunger (based on Figure 4.15), I think that in effect you do have a "safety margin" (i.e. you are using a tighter radius than might be required if you based the selection of radius on the actual yield strength of the material under test).
Drifter, I think you could use either the 1.5" or the 2" diameter plunger. If you go the 2" route, it might be a good idea to file a copy of the material certs with the bend test report, just in case it is questioned later.
Mankenberg