What counts as custom, in three tiers
Buyers say "custom" to mean three different things, and the tiers differ in quantity, timing and paperwork. Tier one is standard geometry with your mark: a catalog square or ball nose, ground to reference geometry, laser-marked with your logo and boxed in your packaging - the lightest form of OEM, typically starting from about 50-100 pieces per specification. Tier two is altered standard geometry: a catalog family with a change your range needs, such as a longer length of cut, a different flute count or a special corner radius value. Tier three is non-standard geometry: a special taper, a compound profile, a form that exists only on your drawing. Tier three is quoted per tool family, always against a drawing, and the drawing quality decides everything downstream.
What a complete drawing carries
A grinding shop can only quote and cut what the drawing states. The lines below turn a sketch into a manufacturable document; anything missing comes back as a question, and each question adds days.
| Drawing element | What to state | Notes for buyers |
|---|---|---|
| Profile view | The tool silhouette with all diameters | A clean side view beats a paragraph |
| Cutting diameter | Nominal value, inch or metric | Name the series; do not mix them |
| Length of cut | Axial flute length | Drives rigidity and reach trade-offs |
| Flute count | 2, 3, 4 or more | Material decides; see the flute guide |
| Helix angle | Degrees, or a named class | High-helix shears aluminum; low-helix calms thin walls |
| Corner / radius | Sharp, or radius value per spec | The radius value is confirmed per spec sheet |
| Shank | Diameter and length | Must match your holders |
| Substrate | Carbide grain class or HSS type | Confirmed by the factory in writing |
| Coating family | TiAlN-family, TiN, none, diamond-family | Uncoated polished for most aluminum work |
| Tolerance basis | Which lines are measured, per program | Agreed before sampling, not after |
What happens on the grinding line
Once the drawing is agreed, the physical sequence is well established across the cluster. Carbide rod is cut into blanks; the flutes are ground on five-axis CNC machines; gashing and corner preparation follow; the cutting edges are honed; if the program is coated, the batch goes to a PVD coating line; the shank is laser-marked with your logo and geometry code; and the tools pass optical measurement of diameter and flute geometry plus a runout check at the cutting edge before boxing. Each step has an owner, and each step's acceptance comes from the sheet you approved. The full walk-through with the process in order is on the production process page, and the route options sit on the custom grinding page.
Timing, as reference ranges
Custom grinding has an honest rhythm, and it is always quoted as a typical reference range confirmed in writing per program. Samples take about 15 to 25 days after the drawing is agreed - the range exists because tier-two changes sample faster than tier-three profiles, and coated samples wait for a coating batch. Bulk takes about 30 to 45 days after sample approval. A coated program adds a few days over uncoated, because grinding and coating are separate steps at separate lines. Anyone quoting a single fixed date for all three tiers is guessing; anyone refusing to put a dated figure in writing is worse than guessing. The reference table lives on the MOQ and lead time page.
Quantity for custom programs
Quantity follows the tier. Tier one - standard geometry with your mark - typically starts from about 50-100 pieces per specification. Tier two follows the same logic when the change is small, but the factory confirms per program because an altered flute count can move a tool into a different setup. Tier three is quoted per tool family with no general figure, because a special profile's setup dominates its economics. The desk's advice is to state your honest sell-through per line item rather than inflating numbers to reach a threshold - a program sized to real demand reorders smoothly, while an inflated one sits in cartons.
Coating choices on custom programs
Coating is a per-program decision with a timing cost worth planning around. The generic families cover most cases: TiAlN-family for steels and dry machining, TiN for general purpose work, uncoated polished flutes for most aluminum, diamond-family coatings for abrasive non-ferrous materials and composites. On a custom program the decision belongs on the sheet before sampling, because coated samples wait for a coating batch, and a mid-program change of family means a new coating run - a few days each time, plus re-marking and re-inspection. Edge preparation interacts with the choice too: a honed edge under a coating behaves differently from a sharp one, and the combination belongs on the sheet as a pair. Confirm both lines in writing, then let the sample settle the question - that is precisely what samples are for.
Approving the sample
The sample is the proof step, and it deserves measurement, not a glance. Measure the geometry lines against the drawing, check the mark against the artwork, look at the coating and the box label, and only then send written approval - because approval is what bulk is inspected against. The common failure is approving from a photograph or from a single cut on one machine; a sample proves geometry, not performance across every workpiece. What to measure and what approval locks in is covered step by step in the sampling post.
When a drawing is not enough
Sometimes the fastest route to a drawing is a worn tool. If your shop already runs a geometry it likes - any brand's - a physically measured sample tool gives the grinding shop the profile to work from, and the desk turns that into a clean drawing for approval. What the desk will not do is copy a competitor's catalog page as a specification; the sheet is written from measured geometry and your confirmed values, which also keeps trademark questions clean. Send the requirement through the quote form with either the drawing or the sample tool's measurements, and the first reply will name the tier, the sampling plan and the open lines.
Practical checklist
- Decide the tier first: your mark on standard geometry, altered standard, or a true special.
- Complete every drawing line: profile, sizes, flutes, helix, corner, shank, substrate, coating.
- Agree the tolerance basis before sampling, not after.
- Expect samples in about 15-25 days and bulk in about 30-45 days, confirmed in writing.
- Size quantities to real sell-through per line item.
- Measure the sample against the drawing, then approve in writing.
- Freeze the approved sheet version before bulk starts.