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Screws · Trade series (trilobular thread-forming screws) · Application guide

What Are Trilobular Metal Thread-Forming Screws Used For?

Typical applications, the industries that specify trilobular metal thread-forming screws, and how to choose the right size, material and finish for the joint.

Trilobular Metal Thread-Forming Screws are used for forming or rolling a mating thread in a prepared hole without cutting conventional chips. They are manufactured to Trade series (trilobular thread-forming screws), and selection is driven by the thread size, the fit and tolerance the assembly requires, and the service environment.

Primary duty
Forming or rolling a mating thread in a prepared hole without cutting conventional chips
Governing standard
Trade series (trilobular thread-forming screws)
Thread size range
M1.0 / M1.2 / M1.4 / M1.6 / M2 / M2.5 / M3 / M3.5 / M4 / M5 to M6 / M8 / M10 / M12 / M14 / M16
Category
Screws

Application notes are general engineering guidance. Verify the property class and any approval requirement against your own design calculation.

What Are Trilobular Metal Thread-Forming Screws Used For? application image

The primary duty of Trilobular Metal Thread-Forming Screws is forming or rolling a mating thread in a prepared hole without cutting conventional chips. Below: the sectors that specify them in volume, the checklist used to select the right size and material for the application, installation notes, and the known limits of the type. Stocked across roughly M1 to M6, they cover light-duty and instrument-scale work.

Typical Applications for Trilobular Metal Thread-Forming Screws

The most common settings where these are specified:

  • Automotive assembly: Trilobular screws form a thread in drilled or punched holes without a loose nut.
  • Appliance production: Case-hardened thread-formers suit high-volume sheet and cast-metal assembly.
  • Electrical equipment: Coatings and profile reduce installation friction in thin metal.
  • Machine building: Metric M1–M16 sizes cover small instrument through larger assemblies.

How to Specify Trilobular Metal Thread-Forming Screws for Your Application

  • Size: Match the nominal size to the mating thread or hole. This product spans M1–M6; check the full table below for the exact dimensions of each size.
  • Drive & head: Pick the drive (socket, cross, slot) and head style for the tool access and seating surface; a recessed drive resists cam-out under power tools.
  • Environment: For damp, coastal or chemical exposure prefer A4/316 stainless or a suitable coating; indoors, plated steel or A2 is usually sufficient.
  • Standard: This product is supplied to Trade series (trilobular thread-forming screws). Quoting the standard on your order guarantees interchangeable dimensions between suppliers.

Installation & Assembly Practice

  • Match the driver exactly to the recess (PH ≠ PZ; hex key sizes per ISO 2936) and keep the tool axial — side load is the main cause of stripped drives.
  • In tapped holes, engage a thread length of at least 1× the nominal diameter in steel, 2× in aluminum.
  • Set power tools to a torque that seats the head without embedding it into the mating surface.

Common Selection Mistakes with Trilobular Metal Thread-Forming Screws

  • Under-sizing the drive for the installation torque — a small recess at high torque strips before the screw is seated.
  • Using a countersunk head in thin sheet where the countersink removes most of the load-bearing material.
  • Specifying stainless in high-strength duty: A2-70 is roughly class 7 steel, not a 10.9 substitute.

Where Trilobular Metal Thread-Forming Screws Are Not the Right Choice

Not for high-preload structural joints (use a property-class bolt and nut), and not in thin sheet where a self-drilling or self-tapping type suits better.

Technical Drawing

Customize the parameters below — every spec field is editable, and the drawing redraws to match the values you choose. Changing the size will snap the other fields to that size's standard values; you can then override any individual value.

Sends the selected values to the quote form below.

Request a Quote

The form below follows the current technical drawing configuration. Change the drawing values above and the request details update automatically.

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Specification
Business Information

Dimensions & Specifications (Trade series (trilobular thread-forming screws))

Thread sizePitch options (mm)ProfileMaterial / coatingLead form
M1.0 / M1.2 / M1.4 / M1.6 / M2 / M2.5 / M3 / M3.5 / M4 / M50.25 / 0.30 / 0.35 / 0.40 / 0.45 / 0.50 / 0.60 / 0.70 / 0.80trilobular thread-forming / rollingcase-hardened steel with corrosion-resistant coatingfour-thread tapered lead
M6 / M8 / M10 / M12 / M14 / M161.0 / 1.25 / 1.50 / 1.75 / 2.0trilobular thread-forming / rollingcase-hardened steel with corrosion-resistant coatingstabilizing and tapered threads
Inside the plant

Manufactured in our own plant

This part is cold-formed, threaded, heat-treated and finished in-house. The stages below are where its class and finish are actually decided.

  1. Wire rod feeding into a cold heading machine
    01

    Cold heading

    Wire rod is drawn to size and cold-formed into blanks. Forming rather than cutting keeps the grain flow continuous around the head, which is where a bolt is most likely to fail.

    Head dimensions and under-head radius checked at set-up and per shift.

  2. Thread rolling machine producing bolt threads
    02

    Thread rolling

    Threads are rolled between hardened dies rather than cut. Rolled threads are stronger in fatigue than cut threads and hold pitch and flank angle far more consistently across a batch.

    Go / no-go ring gauges to ISO 965 tolerance class 6g.

  3. Baskets of bolts staged for heat treatment
    03

    Heat treatment

    Quench-and-temper brings carbon and alloy steel to the property class ordered — 8.8, 10.9 or 12.9 — with the furnace charge tracked so a finished lot can be traced back to it.

    Core hardness and tensile tested per lot to ISO 898-1.

  4. Zinc plated bolts in a treatment basket
    04

    Surface treatment

    Zinc, zinc-nickel, hot-dip galvanizing, black oxide, phosphate and Dacromet, selected against the service environment rather than against the price list.

    Coating thickness and neutral salt spray hours to ISO 9227.

Frequently Asked Questions

Which industries use Trilobular Metal Thread-Forming Screws?

They are commonly specified in machine building, automotive assembly and appliance production, among other sectors.

How do I choose the right size of Trilobular Metal Thread-Forming Screws?

Match the nominal size to the mating thread or hole. This product is available from M1 to M6; the full dimension table on this page lists each size.

What drive type do Trilobular Metal Thread-Forming Screws use?

Drive depends on the head style — socket (hex key), cross (Phillips/Pozi) or slot. A recessed drive resists cam-out when driven with power tools; check the product head style on this page.

What material should Trilobular Metal Thread-Forming Screws be for outdoor use?

For damp, coastal or chemical environments specify A4 (316) stainless or a suitably coated steel. For indoor or dry use, A2 (304) stainless or zinc-plated steel is normally adequate.

Can I get a quote for Trilobular Metal Thread-Forming Screws in the size and material I need?

Yes. Use the technical drawing and quote form on this page to set the size and options, then send the exact configuration to our team for pricing and lead time.