Five coatings on standard part numbers
Coating selection is easier when it is a filter rather than a phone call. Our standard record carries five coating states, and the series prefix tells you which one a part number belongs to.
The states in the catalogue
| State | Typical series | Part numbers on record |
|---|---|---|
| Uncoated / polished | DC326, DC326L | 3,323 |
| TiN (yellow) | HDC636, HDCS636 | 3,162 |
| Black coated | DC426, DC426L | 2,799 |
| Bronze coated | DC836, DC836L | 1,682 |
| DLC (rainbow) | DC336 | 562 |
Reading the prefix
The prefix also encodes geometry. An L at the end of the base code marks an extended-length variant; HD marks left-hand drilling; S marks a step or special form. HDCS636 is therefore a TiN-coated left-hand step drill, and it is the largest single series in the record with 1,508 part numbers.
A practical comparison
Because the same diameter often exists in several coatings, you can hold the geometry constant and change only the surface:
- Filter by diameter band, for example 0.90 to 1.10 mm.
- Compare the
DC326,DC426,DC836andDC336rows. - Ask for one sample of each and run the same programme on the same machine.
A coating change is one variable. Changing coating, flute length and supplier at the same time tells you nothing.
Coating is confirmed in the written quotation, along with the held diameter tolerance for the specific part number.