You can create your own custom arrowheads.
.Arrowheads are stored as block definitions. To use your own arrowhead, provide the name of an existing block definition. For information about creating blocks, see
Arrowhead sizing relies on the overall dimension scale factor. When you create a dimension, the block is inserted where the arrowheads would normally go. The object's X and Y scale factors are set to arrowhead size overall scale. The dimension line is trimmed by text gap x overall scale units at each end. To trim the dimension line, the rightmost block is inserted with a zero rotation angle for horizontal dimensioning. The leftmost block is rotated 180 degrees about its insertion point.
If you use paper-space scaling, the scale factor is computed before applying it to the arrowhead size value.