Thread Forming Screws

Thread forming screws have a lobular, non-circular, fluteless thread profile that displaces material radially as it’s driven in, rather than removing it. This radial displacement plastically deforms, or cold-works, the material immediately surrounding the newly formed thread.

Here is why this matters. Because forming genuinely cold-works the surrounding material as it shapes the thread, this cold working increases the local yield strength of the material right around the formed thread flanks. In a sufficiently ductile material, aluminum, mild steel, many plastics, this means a formed thread can genuinely achieve higher thread strength and stripping resistance than an equivalent-size cut thread in the identical material, because the material around a formed thread has been strengthened by the forming process itself, not just shaped into a thread profile. A cut thread, by contrast, removes material via chip formation and does not produce this same cold-working strengthening effect. This is why thread forming screws are the preferred choice specifically for ductile sheet metal, aluminum castings, and many engineering plastics, where both avoiding chip contamination and maximizing thread strength genuinely matter.

A genuine, honest limitation is worth stating plainly. Because forming relies on the material’s ability to plastically deform and flow smoothly without cracking, thread forming screws are genuinely limited to sufficiently ductile materials. A material that’s too brittle, cast iron, many hard plastics, or thin brittle sheet, will crack or fracture rather than flow smoothly when forced to displace under a forming screw’s lobular profile, producing a weak or damaged thread rather than a strengthened one. Buyers should confirm their material’s genuine ductility, not just assume forming is always the gentler or automatically superior option, since a brittle material actually needs a thread-cutting screw instead, despite forming’s real strength advantage in ductile materials.

Akbar Fasteners Pvt. Ltd. exports to over 50 countries, and our thread forming screw range is manufactured and verified for lobe geometry and mechanical property compliance under our ISO 9001:2015 quality system.