I have just a little more information to share on Ro-taps. ASTM B 214 “Standard Test Method for Sieve Analysis of Granular Metal Powders” describes the sieve shaker as follows. “The number of rotations per minute shall be 270-300. The number of taps per minute 140-160.”
I suggest J-444 and others including AMS 2430 and AMS 2431 revise their specifications to recommend these ASTM Ro-tap requirements. ASTM seems to have done extensive work on this method and I know the two other groups have but maybe not to the extent of ASTM.
The problem is; AMS 2430 and AMS 2431 just finished being published and will not be re-opened for 5 years or else there is a major problem, which I’m not sure if this qualifies.
One other note, we sell a test machine world wide and when we sell to 50 hz customers we have to fit the machine with a different sheave to produce acceptable RPM range. Could this be an option instead of asking to re-open these specifications before the five year reviews?
Dennis Scharer
Ervin Amasteel
Technical Services Manager
