Buy Imperial Thread Forming Taps Online in Australia
Thread forming taps — also called "roll taps" or "fluteless taps" — cold-form threads instead of cutting them. The tap displaces metal sideways into the thread profile, work-hardening the surface and producing a stronger thread than a conventional cutting tap. No chips are produced.
AIMS stocks Sutton imperial thread forming taps across the popular BSW, UNC and UNF sizes.
Why Use a Forming Tap
- No chips — Critical for blind holes, hydraulic components and aerospace work where chip contamination is unacceptable.
- Stronger threads — Cold-working raises tensile strength of the thread flanks by 30-50%. The grain structure flows around the thread profile rather than being cut through.
- Longer tap life — No cutting edges to wear or chip. A forming tap can outlast a cutting tap by 5-10x in ductile materials.
- Smaller tapping drill — Forming taps need a slightly larger pilot hole than cutting taps. Specific drill sizes are stamped on the tap.
When Forming Taps Won't Work
Forming taps require a ductile material — they displace metal, not remove it. Don't use them in cast iron (brittle, no plastic flow), hardened steel above ~30 HRC, or composite materials. They work brilliantly in aluminium, copper, brass, mild steel up to ~30 HRC, soft stainless and many soft alloys.
Lubrication Matters
Forming taps generate significant friction and heat. Cutting fluid is essential — use a forming-specific tapping paste or a sulphurised oil. Dry-tapping a forming tap will weld it into the workpiece. See the Cutting Fluids Guide for material-specific fluid choices.
Sister Tap Collections
Conventional cutting tap collections: Imperial Hand Taps, Imperial Straight Flute Taps, Imperial Spiral Point Taps, Imperial Spiral Flute Taps, Imperial Machine Nut Taps. Parent: Threading.
Common Questions
Tapping drill size for a forming tap? Larger than for a cutting tap of the same thread — typically 5-10% larger. Sutton stamps the recommended hole size on the tap shank. Don't use the standard Tap Size Chart values — you'll strip the thread.
Why is the formed thread shiny? The cold-working process burnishes the thread surface. The flanks are smoother than a cut thread and have a slight work-hardened layer.
Can I use a forming tap on stainless? Soft stainless (304, 316) yes, with the right fluid. Hardened or high-tensile stainless will resist forming and damage the tap.
Need help selecting forming or cutting taps for a job? Call (02) 9773 0122.