Block Shear Strength 1

[eit09]

I have a question on Block shear Strength. In AISC 13th edition on page 16.1-112 equation (J4-5) gives available strength of 0.6F_u. In AISC 9th edition (green book) page 5-77 equation (J4-1) gives available strength of 0.30F_u. Why such the increase in available strength?

 

[eit09]

There is a Design factore of 0.5 needed on the 0.6F_u. So the two different equations end up being the same. Found this information on a little cheat sheet AISC has for bolts welds and connected parts.