A general-purpose range that covers most work
The four material groups below account for most job shop work. A single set of geometries and two or three coatings covers all of them competently.
| Material group | Drill | End mill | Turning insert |
|---|---|---|---|
| Steel, low carbon and alloy | 3-flute, TiAlN | Square, 38 degree helix, TiAlN | CNMG, P grade, CVD |
| Stainless steel | 3-flute, TiAlN | Square or radius, AlCrN | CNMG or DNMG, M grade, PVD |
| Cast iron | 5-flute, TiCN | Square, AlCrN or uncoated | CNMG, K grade, CVD |
| Aluminium | 2-flute polished, uncoated or DLC | 2 or 3 flute, high helix, polished | Polished uncoated, N grade |
Buying one tool instead of a box
Catalogue items are held in stock and can be ordered individually with no minimum, because a job shop frequently needs one or two pieces for a job that will not repeat.
That is deliberately different from how tooling is often sold. Ordering a box of ten to get one tool ties up cash in inventory that may never be used, and in a job shop the next job usually needs a different geometry.
Standardisation that still fits the work
The counterweight to variety is standardisation: fewer coatings, fewer geometries, and a small set of holders and collets that covers the machine spindles in the shop. Every extra variant adds a set-up to learn and a stock item to manage.
A practical middle position is one coating per material group, two or three holder types, and a collet range that covers the common shank sizes. That is enough coverage for most work while keeping the tool crib small enough to manage.
When to move to a special
A special tool is worth considering when a feature cannot be produced with a standard geometry, when the operation takes long enough that a geometry change would save real time, or when a repeating job justifies tooling built for it.
The trigger is usually repetition rather than difficulty. A difficult one-off is rarely worth a special tool, whereas an easy job that runs every month frequently is.
Frequently asked questions
Is there a minimum order quantity?
No minimum on catalogue items, because they are held in stock. Custom geometries and OEM tooling start at fifty pieces per geometry because the grinding set-up has to be amortised, though a smaller trial batch can be produced first.
What is the smallest set of tooling that covers most materials?
In practice, two coatings and three geometries: TiAlN for steel and stainless, AlCrN for stainless and cast iron, a 3-flute drill, a square end mill, and a CNMG turning insert in a P grade and an M grade.
Is it worth buying a special tool for a one-off job?
Rarely. The value of a special comes from repetition, because the development and set-up cost is recovered across the batch. For a one-off, adjusting the process or the part design is usually cheaper.
How do I reduce the number of tools in the crib?
Standardise on one coating per material group and a small holder range, rather than optimising each job for the theoretically best tool. The time saved in set-up and stock control usually exceeds the small performance gain.
Do you supply in small quantities for trial?
Yes. Trial quantities of catalogue items are normal and carry no minimum. For a custom geometry, a small trial batch can be produced before the production quantity is committed.