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Screws · Trade series (three-point service screws) · Application guide

What Are Tri-Point Internal Service Screws for Mobile Devices Used For?

Typical applications, the industries that specify tri-point internal service screws for mobile devices, and how to choose the right size, material and finish for the joint.

Tri-Point Internal Service Screws for Mobile Devices are used for replacing a model-specific internal or exterior service screw with the correct drive and under-head length. They are manufactured to Trade series (three-point service 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
Replacing a model-specific internal or exterior service screw with the correct drive and under-head length
Governing standard
Trade series (three-point service screws)
Category
Screws

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

What Are Tri-Point Internal Service Screws for Mobile Devices Used For? application image

Tri-Point Internal Service Screws for Mobile Devices are used primarily for replacing a model-specific internal or exterior service screw with the correct drive and under-head length. 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 (three-point service screws).

Typical Applications for Tri-Point Internal Service Screws for Mobile Devices

The most common settings where these are specified:

  • Smartphone service: Tri-point screws retain internal shields and brackets.
  • Battery repair: Short under-head lengths prevent contact with nearby cells and boards.
  • Device refurbishment: Model-specific sets preserve the original internal hardware.
  • Electronics laboratories: A dedicated Y000 driver fits the three-point recess.

How to Specify Tri-Point Internal Service Screws for Mobile Devices for Your Application

  • Size: Match the size to the mating part — see the dimension table below for each option.
  • 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 (three-point service 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-Point Internal Service Screws for Mobile Devices

  • 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-Point Internal Service Screws for Mobile Devices 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 (three-point service screws))

Service positionDriveDriver size (mm)Length options (mm)Length referenceUse
internal shield / bracketthree-point0.61.0 / 1.2 / 1.3 / 1.6 / 1.9under headmodel-specific replacement set
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 are Tri-Point Internal Service Screws for Mobile Devices used for?

Replacing a model-specific internal or exterior service screw with the correct drive and under-head length. They are supplied to Trade series (three-point service screws).

Which industries use Tri-Point Internal Service Screws for Mobile Devices?

They are commonly specified in smartphone service, battery repair and device refurbishment, among other sectors.

How do I choose the right size of Tri-Point Internal Service Screws for Mobile Devices?

Match the size to the mating part using the dimension table on this page.

What drive type do Tri-Point Internal Service Screws for Mobile Devices 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.

Can I get a quote for Tri-Point Internal Service Screws for Mobile Devices 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.