Question

The correct sequence of machining operations to be performed to finish a large diameter through hole is

• A. drilling, boring, reaming
• B. boring, drilling, reaming
• C. drilling, reaming, boring
• D. boring, reaming, drilling

Hint:

The correct sequence of operations for creating and finishing a large hole is: drilling (to create the hole), boring (to enlarge and refine), and reaming (to achieve precision and finish).

Answer 1

The Correct Option is A

To finish a large diameter through hole, the sequence of operations follows a step-by-step process to ensure that the hole is the correct size and finished to the required tolerance.
1. Drilling: The first operation is drilling, which is used to create the initial hole. This step removes the bulk of material and creates the rough shape of the hole.
2. Boring: After drilling, boring is used to enlarge the hole and improve the roundness and accuracy of the diameter. This operation removes the excess material to get a closer fit.
3. Reaming: Finally, reaming is done to provide a smooth finish and precise diameter. This operation improves the accuracy of the hole and ensures that it meets the desired specifications.
This sequence ensures that the hole is made efficiently with accurate dimensions and surface finish, so the correct order is drilling, boring, reaming, which is option (A).