Buy Slot Drills Online in Australia
Slot Drill Selection — Quick Reference (2-Flute End Mill)
Slot drill = 2-FLUTE END MILL designed to PLUNGE directly into material + cut slots + keyways + pockets WITHOUT pre-drilled start hole. 2-flute geometry = chip clearance for plunging + slotting work where 4-flute end mill packs chips.
| Slot Drill Type | Best For |
|---|---|
| Standard 2-Flute Slot Drill | Slot + keyway + general plunge milling |
| Centre-Cutting Slot Drill | Can plunge straight down — end-mill geometry |
| HSS Standard | Mild + low-alloy steel |
| HSS Cobalt | Stainless + tough materials |
| Solid Carbide | Production + extended life + high speed |
| Coated (TiN / TiAlN) | Extended life + production |
| Common Diameters (3-25mm) | Match to slot width required |
| Long-Series | Deep slots + cavities |
Critical: 2-flute = plunge capable BUT slower finish than 4-flute (less cutting edges). For SLOTTING specifically — use full slot drill (2-flute); for FACING + side milling = 4-flute or higher. Cutting fluid + correct feed/speed per material. Match diameter EXACTLY to slot width — usually undersize then finishing pass. Brands: Sutton Tools, Bordo. Companion: end mills, square end mills, end mill guide.
Slot Drills for Milling and Slot Cutting in Australian Engineering
A slot drill is a 2-flute end mill designed to plunge directly into material and cut slots, keyways, and pockets without a pre-drilled start hole. The 2-flute geometry with centre-cutting end geometry allows axial plunge cutting — the defining feature that separates a slot drill from a 4-flute end mill, which can't plunge cut reliably. AIMS Industrial stocks HSS slot drills from Sutton Tools and Bordo for Australian machining, toolmaking, and engineering customers.
Slot drill vs end mill: when to use which
- Slot drill (2-flute) — use when the cut starts in solid material (plunge entry), for keyway cutting, and for slotting where chip evacuation matters. The 2-flute geometry gives more chip clearance in the cut
- End mill (4-flute) — use when machining from an existing hole or edge (no plunge needed); provides a better surface finish on finishing passes due to more cutting edges. Not suitable for plunge cutting
Common applications
- Keyway cutting — slot drills are the standard tool for milling keyways in shafts and bores; the slot width is matched to the Woodruff key or parallel key dimension
- Pocket milling — for enclosed pockets where the cutter must enter from the top, plunge to depth, then ramp or helical interpolate to full pocket depth
- T-slot and dovetail preparation — roughing the slot before the T-slot or dovetail cutter passes
- General slotting — any through-slot where chip clearance is important
Sizes and materials stocked
Common diameters stocked range from 3mm through 25mm in standard metric steps. HSS slot drills are the general-purpose choice for steel and aluminium; TiN-coated HSS improves tool life in harder materials and production applications. For difficult-to-machine materials or high-volume work, carbide slot drills are available — enquire directly.
Cutting parameters
Slot drills require lower spindle speeds and feed rates than equivalent-diameter drills — cutting speed in steel is typically 20–30 m/min for HSS; divide by π × diameter to get RPM. Use a rigid machine setup; slot drills are more susceptible to chatter than end mills due to fewer cutting edges. Apply cutting fluid, particularly for stainless steel and harder alloys.
Related cutting tools
See also: square end mills (4-flute) for surface finishing cuts, drill bits for drilling to depth before milling, and reamers for finishing bores to tolerance.
For specific diameter, flute length, or coating requirements, contact our team.