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Screws · Trade series (Tri-Wing pan-head screws) · Application guide

What Are Tri-Wing Pan-Head Machine Screws Used For?

Typical applications, the industries that specify tri-wing pan-head machine screws, and how to choose the right size, material and finish for the joint.

Tri-Wing Pan-Head Machine Screws are used for securing a panel or internal bracket with a three-wing recess and the correct service driver. They are manufactured to Trade series (Tri-Wing pan-head screws), and the choice of size, property class and finish is driven by the load in the joint and the environment it sits in.

Primary duty
Securing a panel or internal bracket with a three-wing recess and the correct service driver
Governing standard
Trade series (Tri-Wing pan-head screws)
Thread size range
M3 to M8
Category
Screws

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

What Are Tri-Wing Pan-Head Machine Screws Used For? application image

Tri-Wing Pan-Head Machine Screws are used primarily for securing a panel or internal bracket with a three-wing recess and the correct service driver. This page lists the industries and assemblies where they are specified, the selection criteria that matter for each application, installation practice, and the cases where a different fastener type is the correct choice. Parts are supplied to Trade series (Tri-Wing pan-head screws). Stocked across roughly M3 to M8, they cover general to heavy-duty work.

Typical Applications for Tri-Wing Pan-Head Machine Screws

The most common settings where these are specified:

  • Appliance service: Tri-Wing drives reduce casual removal from consumer housings.
  • Electronics: A2 stainless pan heads fit compact covers and shields.
  • Battery equipment: Blackened or coated options match the surrounding finish.
  • Production assembly: Drive sizes W2 through W7 follow the thread size.

How to Specify Tri-Wing Pan-Head Machine Screws for Your Application

  • Size: Match the nominal size to the mating thread or hole. This product spans M3–M8; 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 (Tri-Wing pan-head 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 Tri-Wing Pan-Head Machine 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 Tri-Wing Pan-Head Machine 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.

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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 (Tri-Wing pan-head screws))

Thread sizeHead diameter (mm)Head height (mm)DriveLength range (mm)Material / finish
M35.61.8W26~25A2 stainless / blackened / Nylok-coated
M48.172.92W46~30A2 stainless / blackened / Nylok-coated
M59.473.37W510~50A2 stainless / blackened / Nylok-coated
M612.494.44W610~50A2 stainless / blackened / Nylok-coated
M815.625.53W710~50A2 stainless / blackened / Nylok-coated
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

What material should Tri-Wing Pan-Head Machine 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.

Are Tri-Wing Pan-Head Machine Screws made to a recognized standard?

Yes — they are manufactured to Trade series (Tri-Wing pan-head screws), so dimensions are interchangeable between suppliers when you quote the standard on your order.

What are Tri-Wing Pan-Head Machine Screws used for?

Securing a panel or internal bracket with a three-wing recess and the correct service driver. They are supplied to Trade series (Tri-Wing pan-head screws).

Which industries use Tri-Wing Pan-Head Machine Screws?

They are commonly specified in appliance service, electronics and battery equipment, among other sectors.

Can I get a quote for Tri-Wing Pan-Head Machine 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.