Why you need a numbering scheme
Without a shared scheme everyone names tools their own way: “end mill 10”, “ENDMILL D10 Z4”, “em.10”. The result is duplicates in the tool list, wrong orders, and tools that look missing while they sit in the crib under another name. One unique code per tool fixes all of this, as long as it follows a few clear rules that everyone keeps.
The structure: category, size, sequence
The sturdiest scheme has three fixed-length parts. For example EM-0100-0001:
- EM is the category: two easy letters (EM end mill, DR drill, TP tap, IN insert).
- 0100 is the main size in tenths of a millimetre, always four digits: 0100 means 10.0 mm, 0068 means 6.8 mm.
- 0001 is a sequence number with no meaning, separating tools of the same category and size.
Fixed length keeps codes sorting correctly in any list, and the size in the code lets you spot a tool at a glance, without reading the description.
What to keep out of the code
Only what never changes goes into the code. Keep out:
- price and crib location, which change over time;
- secondary features (flutes, coating, helix angle), which belong in the description.
Be careful with the brand, though: two Ø10 end mills from different makers are not the same tool. Geometry, grade, coating, tool life and cutting data differ, and often the machine program parameters too. So every item from every maker gets its own code: if one day you switch brand, you create a new sequence number and the history stays clean, with each tool's performance where it belongs. Brand and maker's part number live in two fields of the tool record, linked to the code.
The description does the rest
The code identifies, the description explains. Write it in the same order every time: type, material, size, features. For example “End mill carbide Ø10 4FL 30° helix” or “Drill carbide Ø6.8 for M8”. With a fixed order descriptions are easy to compare and duplicates stand out.
How to avoid duplicates
- Before creating a new code, search by category and size: if the same item exists, same maker and same catalogue number, use it.
- One person, or one clear role, approves new codes.
- Codes are never reused: a retired tool stays in the list as “no longer in use”.
- No catch-all categories like “MISC”: they become the place for everything nobody wanted to classify.
Moving off Excel
Starting from a spreadsheet, work in this order: export the list, standardise descriptions in the chosen order, group by category and size, flag duplicates, and only then assign the new codes. Keep a column with the old code, so for a few months both names live side by side without mistakes.
The most common mistakes
- Codes too long to read out over the phone.
- One code shared by tools of different brands “because they are the same”: they are not, and the history stops meaning anything.
- Sizes written without fixed length (10, 6.8, 06.80).
- A new category for every new purchase, until there are fifty of them.
Ten to fifteen well-chosen categories cover almost every turning and milling tool room.