A bolt circle is a pattern of holes about a central point. All center points of these holes are an equal radius from a central point of rotation.
Creating the Feature in Solidworks
To create a bolt circle in Solidworks, first create the first hole using the Hole Wizard. This hole should be dimensioned off of a central axis or feature on the part that the bolt circle will be rotated about. Generally the first hole has a specified radius from the central axis as well as an angle that it is offset from vertical.
Then use Circular Pattern to pattern this first hole around the central axis or feature, or create multiple holes by creating and dimensioning more points.
First, create center marks by selecting the center mark creator from the Annotations tab. Select the bolt circle center mark, then select all holes in the bolt circle in a single view to create a center mark and bolt circle radius construction line.
Create a radius dimension for the radius of this bolt circle. In the line under the dimension, type "B.C. RADIUS"
Determine which hole will be the initial hole. If this hole is not vertical or horizontal to the center of the circle, dimension the angle it is offset from a reference angle or feature.
Create an offset angle dimension between this hole and the next hole in the B.C. pattern. Type "N_x_" (where N is the number of holes this offset applies to, generally total number of holes - 1, and "_" are spaces) before the dimension. More of these dimensions may be needed if inconsistent angles are used between holes.