Sandvik Coromant Recommendation Use all 8 Edges of CNMG Insert instead of Just 4

The most popular turning insert in the industry is the 80 degree diamond (CNMG insert).

Sandvik Coromant CNMG insert

Sandvik Coromant CNMG insert

Known for its balance of versatility and edge strength it is usually the first choice of CNC programmers.

Related: Sandvik Coromant Catalogue pdf Free Download

Sandvik Coromant CNMG insert is known for its balance of versatility and edge strength

Sandvik Coromant CNMG insert is known for its balance of versatility and edge strength

However, many customers use the four 80 degree corners of CNMG insert and discard the other four cutting edges found on the 100 degree corners.

Related: General Turning Insert Nomenclature for CNC Dummies

While applying the 100 degree corner is more difficult because it cannot face to a shoulder and requires a separate tool (DCRNR tool, DCKNR tool or DCBNL tool), there are applications where a tool like this can help you.

CNMG insert 100 degree edge usage through a DCBNL turning tool for roughing operation

CNMG insert 100 degree edge usage through a DCBNL turning tool for roughing operation

Take a look around your shop for OD roughing turns that do not require a square shoulder. Also facing operations are a perfect place to apply the 100 degree corner. Both of these types of applications allow you to make full use of the CNMG insert.