Unable to generate NC drill to mechanical pin

Tool Num Size +/- Tolerance Plating Quantity

T20 1. 20.0000 0.0000/ 0.0000 PLATED 399

T28 2. 28.0000 0.0000/ 0.0000 PLATED 78

T40 3. 40.0000 0.0000/ 0.0000 PLATED 91

4. 138.0000 0.0000/ 0.0000 PLATED 0 ---- Can't find toolcode in nc_tools.txt

WARNING: Some toolcodes not found in 'nc_tools.txt' file.

Any one give the solution for this.

Thanks in advance

Siva