In seismic category E, what is the required anchor bolt diameter?

• A. 1/2 Inch
• B. #5
• C. 5/8 Inch
• D. 3/4 Inch

Answer: (C)

In seismic category E, the anchor bolts must provide enough capacity to resist the higher uplift and shear forces that come with strong shaking. The minimum diameter specified for this category is 5/8 inch because a larger cross-sectional area gives the bolts greater strength to hold the connection under seismic loads. A 1/2 inch bolt doesn’t meet that required capacity, while a 3/4 inch bolt would be more than enough but isn’t the minimum mandated by the standard. So the necessary and correct diameter is 5/8 inch.