×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

bend radius vs bottom die opening for press brakes

bend radius vs bottom die opening for press brakes

bend radius vs bottom die opening for press brakes

(OP)
My question is concening bend radius vs die opening.  Is it possible to use one nose radius with a variety of die openings to achieve different inside bend radii?  For example, if I have a 3/16" nose radius could I get a 3/8" radius for 3/8" material, 1/4" radius for 1/4" material, and so on, just by varying the bottom die opening?

RE: bend radius vs bottom die opening for press brakes

In practical use, die opening does not affect the radius as much as the nose radius of the punch, but die opening does affect tonnage.

RE: bend radius vs bottom die opening for press brakes

Basically, the press brake process is a forming process, where you form the radius with the top die set. The bottom die set is used to control the angle of the form by supporting the material during the forming process. You will need a nose radius for each bend you want to acheive.

RE: bend radius vs bottom die opening for press brakes

Generally, the radius is controlled by the radius of the punch, rather than the die width, but the die width is an important factor.  Not only does it affect tonnage, but by using larger die widths, the radius is increased.  At one company we used 8 times the material thickness to find the die opening, and at another company we used 6 times the material thickness (different company standards).  Using the same radius punch, the smaller die opening produced a tighter radius.  

IT IS possible however to use one nose radius to achieve different inside bend radii if you do not have the correct tooling for a project.  By adding a "cap" or "wrap" to the punch, you can increase the radii, however the thickness of the cap should generally be equal to or thicker than the material being formed.  
Note: by a cap, I mean forming a piece of sheet metal into a "V" shape to fit snuggly over the punch, with the flanges having a bend in them to grip the punch by friction, and also a little bit of duct tape to hold it on.
We have used this on lighter gauges, up to 10 gauge.  
For example, you have a 1/8" punch, and you are forming 16 ga. mild steel and you need an inside radius of 1/4".  By making a cap of 11 ga. mild steel and put it on the 1/8" punch, you now have a punch that will form an inside radius of 1/4" to 5/32".  (.125 + .120 = .245)
The bottom die width will have to be increased accordingly.  

Flores

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources