Oriented drill core protractor templates / Транспортирные шаблоны для ориентированного бурения

Each of the following pages contains a protractor for a specific size of drill core. 

Choose the appropriate chart for the drill core size. Check the core diameter to choose the appropriate template within each core size grouping.

The protractors are in two groups: beta angle protractors and alpha/beta angle protractors. In practice I find that the beta angle protractor alone is best as it is least cluttered with lines (and alpha angles are easily measured using a protractor). <...>