A single point cutting tool of nomenclature 0-7-7-7-15-15-1/32 has the back rake angle of-

Explanation:

ASA tool signature has 7 elements

American Standards System (ASA) system ⇒ Back rake angle – side rake angle – end relief angle (ERA) – side relief angle – end cutting Edge angle – side Cutting Edge Angle- Nose Radius

Calculation:

Given:

A single point cutting tool of nomenclature is given as,

0-7-7-7-15-15-1/32 

From above, the Back rake angle is 0°

Additional Information

Another tool signature used is,

Orthogonal Rake system (ORS) or International system ⇒ I (inclination angle) – αn (Normal rake angle)  - Side relief angle- end relief angle, end cutting edge angle – Approved angle – nose radius

In both the system nose radius comes in the last.