Metric Spiral Flute Taps

Metric Spiral Flute Taps

Spiral flute taps are the right choice for cutting threads in blind holes — the helix angle of the flutes lifts chips back up and out of the hole, instead of packing them down at the bottom where they jam the tap and ruin the thread. AIMS Industrial stocks metric spiral flute taps for fitters, machinists, and toolmakers working in steel, stainless, alloy, and non-ferrous materials.

Why spiral flute taps

• Blind holes — chips evacuate up and out, not down into the bottom of the hole
• Soft and gummy materials — the helix shears the chip rather than tearing it, giving a cleaner thread
• Powered tapping — better suited to CNC and tapping head use than straight-flute hand taps
• Aluminium, copper, and stainless — long, stringy chips that would clog a straight-flute tap clear easily through a spiral

Sizes and pitches

We stock metric coarse from M2 to M24, plus the common metric fine pitches (M8×1, M10×1, M10×1.25, M12×1.25, M12×1.5, M14×1.5, etc.). Helix angles vary by application — 15°-25° for general steel, 35°-45° for aluminium and other long-chip materials.

Brands and coatings

The range includes Sutton Tools, Bordo, and Champion in HSS and HSS-E (cobalt) grades. Coating options include bright (general purpose), TiN (extended life in steel), TiCN (harder steels), and TiAlN (high-temperature work in tough alloys).

Tapping practice

Match the helix angle to the material, drill to the correct tapping drill size, and use a quality tapping fluid (Molycut, Tap Magic). Spiral flute taps prefer to be driven by a tapping head or CNC — they're not as forgiving as straight-flute taps in a hand wrench.

Helix angle — match it to the material

The helix angle of the flutes drives chip evacuation. Low-helix taps (15-25°) suit harder, short-chip materials like medium-carbon steel and stainless. Medium-helix (25-35°) is the all-rounder for general workshop use. High-helix (35-45°) is for long-chip, gummy materials like aluminium, copper, and softer alloys — the steeper helix lifts chips out fast before they pack and jam. If your work mix is heavily one material, match the tap to it; if it's varied, medium-helix covers most of the work.

Coatings worth paying for

TiN-coated HSS spiral flute taps roughly double tap life in steel over uncoated. TiCN handles harder steels above 35 HRC. TiAlN and AlTiN are the right call for stainless and tough alloys at higher cutting speeds. For low-volume general work, uncoated HSS-E (cobalt) is often the most economical balance.

Choosing the right tap

Not sure whether your application needs spiral flute or spiral point? contact our team — we'll talk through hole type, material, and operation to get you the right tap first time.