Jump to content
Mechanical Engineering

Drilling in Aluminum


Recommended Posts

Hi

We have a CNC drill process to drill multiple holes in to aluminum profiles.

Currently we are using a 10mm dia. end mill

The holes are straight through the profile to give access to fixings which are using at the assembly stage

We are getting a slight burr on the exit hole and I wonder if anyone has recommendations for cutter feed and rotation speeds, type of end mill flutes etc.?

We are cutting dry because the work is for the food industry so contamination would be an issue

I am setting up a machine maintenance program and just want to consider all aspects before I just recommend something like a daily cutter change 

Link to comment
Share on other sites

I think using an end mill will be difficult to prevent the burr...its the form of the cutter; though not only!

Mechanically speaking, there is a force pushing down on the metal at each point of the cutter which reaches a peak at each of the cutting tips, exceeds the elastic limit of the material and - through the geometry of the cutter - shears off the metal. This is the cause of the cutting action and normally occurs in a continuous motion.

As the cutter approaches the end of the material, there is nothing behind the workpiece to resist the downward force, resulting in the metal pushing out into the free space, thus creating the burr as a result of the pressure boundary.

There are normally a couple of ways to address this:

1. a sacrificial plate - an advantage of using an end-mill is the known accuracy of the depth of the drill...a sacrificial plate need only be 1mm! This plate will need to be replaced after every unit, but it will give the additional support that is required to minimise the burring.

2. undertake a separate deburring operation after the initial machining.

Hope this helps

Bruce

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Join Mechanical Engineering network

    Join us (login) to get full access : Please sign up to connect and participate.

    To download files...please login

  • Who's Online   0 Members, 0 Anonymous, 15 Guests (See full list)

    • There are no registered users currently online


×
×
  • Create New...