What is in this group
| Family | Covers | Reach for it when |
|---|---|---|
| Solid carbide drilling | Twist drills, micro drills, 3 and 5-flute, coolant-through, spot drills | A hole is needed and depth or material rules out high-speed steel |
| Milling cutters and end mills | Square, ball nose, corner radius, high-feed, roughing, thread mills | A face, slot, profile or 3D contour has to be produced |
The decision that runs through both
Both families are selected from the same two facts: how much chip room the material needs, and how rigid the setup is.
A free-cutting material that produces long chips needs fewer flutes and more gullet volume. A hard material that produces short chips needs more flutes and a stronger edge. A long reach or a light machine pushes the choice towards fewer flutes and a lower helix, because force has to be minimised rather than edge strength maximised.
- Flute count from the chip the material produces
- Helix angle from the material and the rigidity of the setup
- Point angle from the hole requirement, not from habit
- Coolant delivery from the depth, once three times diameter is exceeded
- Runout at the holder matters as much as the tool geometry
Where the two overlap
Thread mills and some slotting operations sit between the two: a thread mill is a milling tool producing a hole feature, and a slot drill is a drill being used to plunge. That overlap is why the two families are grouped rather than separated, and why a single enquiry frequently covers both.
In this group
2 page(s)
Solid Carbide Drills
Precimill manufactures solid carbide drills from 0.5 mm to 32 mm: 3-flute and 5-flute designs for steel, coolant-through drills for depths beyond three times diameter,...
Read moreMilling Cutters and End Mills
Precimill manufactures solid carbide end mills in square, ball nose, corner radius, high-feed and roughing geometries from 0.5 mm to 25 mm, plus thread mills. Shanks are...
Read moreFrequently asked questions
Which group should I start from?
Start from the feature. A round hole that goes all the way through is drilling; anything with a flat face, a slot, a shoulder or a contour is milling. If the feature is a thread, tell us whether the hole is blind or through, because that decides between a tap and a thread mill.
Do I need a coolant-through tool?
Only when the depth exceeds roughly three times the diameter, or when the material makes chip evacuation the limiting factor. Below that, external coolant is adequate and a coolant-through tool adds cost without adding capability.
Why does runout matter more here than in turning?
In turning the tool is held rigidly and the workpiece rotates, so a small tool error is averaged out. In drilling and milling the tool is a cantilever, so runout loads one flute harder than the others and that flute fails while the rest still have life.
Can the same tool cover steel and aluminium?
The geometry can, but the coating should not. Steel wants a hard coating such as TiAlN or AlCrN, and aluminium wants a polished or DLC surface that prevents built-up edge. Using a steel coating on aluminium is the most common cause of a smeared finish and an oversize hole.
How do I choose between a drill and a boring operation?
Drilling produces the hole and boring corrects it. If the tolerance is tighter than a drill can hold, or the hole must be exactly on centre, drill undersize and bore to size. Boring also corrects a hole that has drifted, which drilling cannot.