---
title: "100kGarages:  CNC Router Bits Demystified"
description: "Early on in planning the design for the (/quadrotor.html \"Custom Made Quadrotor – Overview\"), we knew that eventually some of the metal parts would need to be milled. Having…"
canonical: "https://www.baldengineer.com/100kgarages-cnc-router-bits-demystified.html"
author: "James Lewis"
date: "2013-04-23T09:28:14Z"
lastmod: "2015-06-22T00:25:26Z"
image: "https://www.baldengineer.com/wp-content/uploads/2013/04/cover-photo2.jpg"
categories: ["around-the-web"]
tags: ["bits","cnc","milling","mills","routers"]
---

# 100kGarages:  CNC Router Bits Demystified


Early on in planning the design for the [Quadrotor](/quadrotor.html "Custom Made Quadrotor – Overview"), we knew that eventually some of the metal parts would need to be milled.  Having very little milling experience, other than a couple of basic-use classes at TechShop, I had no milling experience.  When it came time to start buying router bits for the ShopBot and Tormach CNC routers, I didn't know what kind of bits were necessary.

## Understanding End Mills

Greg over at [100kGarages](http://100kgarages.com) put together a primer titled [CNC Router Bits Demystified](http://www.100kgarages.com/blog/2013/04/cnc-router-bits-demystified/), which does a great job of explaining the basics of an End Mill, Ball Nose, Downcut, Upcut etc.

## Recommendations

In his Article, Greg mentions some bits he recommends.  From my experience so far here are the 3 Carbide mills I bought, which are sold through Amazon (direct links):

- [1/2" End Mill 2-Flute](http://www.amazon.com/gp/product/B0020B9PBW/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B0020B9PBW&linkCode=as2&tag=baldengineer-20&linkId=GU2FXLNQQMKUNVPM "End Mill via Amazon").  \- This is really good for hogging out massive amounts of material or quickly cutting profile (cut outs).
- [1/4" End Mill 2-Flute](http://www.amazon.com/gp/product/B0020B2IB6/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B0020B2IB6&linkCode=as2&tag=baldengineer-20&linkId=AQ3VKAU5ICBDTE27 "End Mill on Amazon").  This is the workhorse bit I have been using for my projects, which have a relative amount of detail.
- [1/8"](http://www.amazon.com/gp/product/B0080AZSNG/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B0080AZSNG&linkCode=as2&tag=baldengineer-20&linkId=ON3FARO3YMFKBEZQ) or [1/4"](http://www.amazon.com/gp/product/B0080AZW78/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B0080AZW78&linkCode=as2&tag=baldengineer-20&linkId=MZC3FMMDB5JYFC45) Ball Nose End Mill 4-Flute.  - If you want a nice finished edge or smoother 3d milling features, a ball nose is necessary.  I have both a 1/8" and 1/4" ball nose, but have found it is pretty easy to snap a 1/8" while its results aren't significantly better than the 1/4".

Also, for the smaller bits, you should probably go ahead and buy two.  You are going to break a bit.  When it happens, review your feeds and speeds then try again.