# M3 Hardware

## M3 Hardware Basics

The REV DUO build system uses [M3 hardware](https://www.revrobotics.com/ftc/hardware/fasteners/) to connect, or fasten, brackets and structure together on a robot. Different applications require different length screws. When attaching a bracket to extrusion, shorter screws are generally required. Use longer screws to connect Control System components and other thicker materials.

![](https://756878072-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-M5yw0n8IneF5-9ybLjT%2F-MBdaAEM_fx2eAmY_r3b%2F-MBdecpvUjZ0yPGnieHq%2FM3_Nut_Nyloc_Nut_Hex_Head_Screw.png?alt=media\&token=c9c22723-35b9-4ad9-9525-584301d881c8)

{% hint style="info" %}
*See the* [*“Tips and Tricks”*](https://docs.revrobotics.com/duo-build/building/tips-and-tricks) *section of this guide for best practices when working with the M3 Hardware.*
{% endhint %}

##  Tools

We include all the tools needed to use the parts in the FTC Starter Kit. Take a moment to identify the tools below: 

* 5.5mm Nut Driver ([REV-41-1119](https://www.revrobotics.com/rev-41-1119/))
* 5.5mm Combination Wrench ([REV-41-1374](https://www.revrobotics.com/rev-41-1374/))
* Allen Wrench Pack (1.5mm ([REV-41-1376](https://www.revrobotics.com/rev-45-1882/)), 2mm ([REV-41-1377](https://www.revrobotics.com/rev-41-1377/)), and 2.5mm Allen Wrenches) 
* \#25 Chain Tool ([REV-41-1442](https://www.revrobotics.com/rev-41-1442/))

As robots become more complex, there are additional tools, hardware, and fasteners available on the REV website: 

* 5.5mm Ratcheting Combination Wrench ([REV-49-1711](https://www.revrobotics.com/rev-49-1711/)) 
* Metric Step Drill ([REV-49-1455](https://www.revrobotics.com/rev-49-1455/)) for drilling holes of different sizes
* Zip Ties ([REV-41-1161](https://www.revrobotics.com/rev-41-1161/))
* Hook and Loop Fastener ([REV-41-1373](https://www.revrobotics.com/rev-41-1373/)) 
* Variety of replacement screws, and additional screw lengths

## T-Slot Screws

![](https://756878072-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-M5yw0n8IneF5-9ybLjT%2F-MBdaAEM_fx2eAmY_r3b%2F-MBdeggMe8oZqZuzjWyJ%2FM3_T_Slot_Screw-01.png?alt=media\&token=31b0fbec-87ec-4d6a-a380-08fec297f98d)

Another type of hardware included in the kit is the T-Slot Screw ([REV-41-1907](https://www.revrobotics.com/rev-41-1907-pk25/)). These screws have a T-shaped head allowing them to drop in the slots of the [Extrusion](https://www.revrobotics.com/ftc/structure/15mm-extrusion/) or[ C Channel](https://www.revrobotics.com/competition/ftc/structure/channel/). This allows for modification of an existing design by adding in brackets and structure without needing access to the end of a slot.

{% hint style="warning" %}
Even though T-Slot Screws are convenient, it is always recommended to use full Hex Head Screws because they are a stronger fastener. 
{% endhint %}

### Product Specs 

* Material: Corrosion resistant zinc plated steel
* Length: 8mm

## How to Use?

![](https://756878072-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FH9K1InCLC1ZxIkdPJt31%2Fuploads%2FW0iVhFEB0bS4CHFQP4wB%2Ft-slot%20drop%20ins.png?alt=media\&token=c8ecfee0-0d0a-4cc4-b7dc-17be7f5e1860)

Simply drop the t-slot screws into the channel where you want them to go and attach the brackets or structures you want and tighten until [snug](https://docs.revrobotics.com/duo-build/building/tips-and-tricks#snug-not-stuck). 

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