---
title: "What Are Tri-Point Internal Service Screws for Mobile Devices Used For?"
description: "Tri-Point Internal Service Screws for Mobile Devices (Trade series (three-point service screws)) are used for replacing a model-specific internal or exterior…"
url: https://engineeringhardware.com/applications/tri-point-internal-service-screws-for-mobile-devices/
source: Engineering Hardware & Fasteners
---

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

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

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](https://engineeringhardware.com/wp-content/uploads/2026/09/Apple-iPhone-Y000-Tri-Point-Internal-Screws.webp)

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.

Product catalog

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## 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.

Custom manufacturing · Made to drawing

## Need a tri-point internal service screws for mobile devices outside the standard range?

Lengths and thread lengths outside the standard table are the commonest request, followed by a drive the standard does not offer and a head marked with your own part number. Made by cold heading or warm forging.

Minimum order from 2,000 pieces; samples within 7 days of drawing approval.

[Custom screw manufacturing](https://engineeringhardware.com/custom/screws/)[Send a drawing](https://engineeringhardware.com/custom/screws/#rfq)

## Technical Drawing

Dimensioned line drawing of internal shield / bracket Tri-Point Internal Service Screws for Mobile Devices to Trade series (three-point service screws). Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected.

- **Drive:** three-point
- **Driver size (mm):** 0.6
- **Length options (mm):** 1.0 / 1.2 / 1.3 / 1.6 / 1.9
- **Length reference:** under head
- **Use:** model-specific replacement set

## Dimensions & Specifications (Trade series (three-point service screws))

| Service position | Drive | Driver size (mm) | Length options (mm) | Length reference | Use |
| --- | --- | --- | --- | --- | --- |
| internal shield / bracket | three-point | 0.6 | 1.0 / 1.2 / 1.3 / 1.6 / 1.9 | under head | model-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](https://engineeringhardware.com/wp-content/uploads/2026/08/09-wire-rod-feed-cold-heading-machine.webp) 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](https://engineeringhardware.com/wp-content/uploads/2026/08/03-thread-rolling-machine-bolt-production.webp) 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](https://engineeringhardware.com/wp-content/uploads/2026/08/05-heat-treatment-baskets-black-bolts.webp) 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](https://engineeringhardware.com/wp-content/uploads/2026/08/23-zinc-plated-bolts-treatment-basket.webp) 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.

## Related Pages

Product page: [Tri-Point Internal Service Screws for Mobile Devices — specifications & sizes](https://engineeringhardware.com/fastener/tri-point-internal-service-screws-for-mobile-devices/)

### Tri-Point Internal Service Screws for Mobile Devices Specification Guides

### Related Fastener Applications