Metric Straight Flute Taps

Metric Straight Flute Taps

Straight flute taps are the general-purpose workhorse of metric thread cutting — the geometry is symmetrical, the cutting action is well-understood, and they suit the largest range of materials and operations. AIMS Industrial stocks metric straight flute taps for fitters, mechanics, and machinists who need a single tap style that handles the everyday mix of tapping work in a workshop.

Where straight flute taps work best

• Through-holes in steel, brass, and bronze — chips clear forward and back without jamming
• Cast iron and free-machining materials — short, broken chips that don't need a helix to evacuate
• Hand tapping — the symmetric geometry tolerates the start-stop rhythm of a tap wrench
• General workshop and maintenance use — the single style that covers most of the work most of the time

Sizes and pitches

Our metric straight flute tap range covers M1.6 to M30 in coarse pitch, plus all the common metric fine pitches. Hand tap sets (taper, intermediate, bottoming) are stocked alongside individual machine taps.

Brands and grades

HSS-grade Sutton Tools, Bordo, and Champion are the core stocked brands, with HSS-E (cobalt) available for tougher materials. Surface treatments include bright finish, steam tempered, TiN, and TiCN — chosen by application.

When NOT to use straight flute

Straight flute taps are not the right choice for blind holes in long-chip materials like aluminium or stainless — the chips pack at the bottom, jam the tap, and tear out threads. For those applications, spiral flute taps are the fix. For high-speed production in through-holes, spiral point (gun) taps push chips forward and clear of the cut.

Coatings — when each one earns its keep

Bright finish (uncoated) is the cheapest, suits low-volume work and easy materials, and is fine for one-off threading. Steam-tempered finish (blue-black) handles cast iron and abrasive materials better and improves chip flow. TiN coating (gold) extends life by 2-3× in steel — pays back fast on production work. TiCN suits harder steels above 35 HRC. TiAlN is for high-speed, high-temperature work in stainless and tough alloys. For most general workshops, TiN-coated HSS hits the sweet spot of price and performance.

Resharpening

HSS hand taps can be resharpened by a competent tool grinder once or twice over their life, which is worth doing on the larger sizes (M16+) where new tap cost is meaningful. Smaller sizes (M6 and below) are economical to replace rather than resharpen. Coated taps lose their coating advantage after resharpening.

Need set or size advice?

contact our team for tapping drill charts, set recommendations, or sourcing on less common metric fine pitches. AIMS Industrial has supported Australian workshops with quality cutting tools since 1988.