[Amps] Bend allowance

[Will Matney]

Ian,

You can use a radius inside bend instead of a sharp 90, use a soft aluminum, or use a bottoming die which holds pressure on the outside. The bottoming die wont do you any good though on a pan/box break, just V-dies types. Sharp 90 deg bends is a major cause in brittle types of aluminum. A 1/8" radius will help a good bit. To do this in a break, you have to add a shoe over the fingers on a pan break, or a radiused punch on a V brake. Anytime you see that cracking, it's because your using too sharp of a bend for the material. That's the only ways I know to do it.

Best,

Will


*********** REPLY SEPARATOR  ***********

On 8/4/05 at 8:11 AM Ian White G/GM3SEK wrote:

>N7KA wrote:
>>Someone asked about bend allowance for sheet metal.  If needed contact 
>>me off line as I have info needed to do calcs from work.  We de do a 
>>LOT of sheet metal fab work and forming is ongoing continuous process 
>>for us (mostly  aluminum up to .25 inch).
>
>Staying on-line... what's the trick to prevent alumin(i)um from 
>splitting on the outside edge of a bend where it is stretched?
>
>
>-- 
>73 from Ian G/GM3SEK         'In Practice' columnist for RadCom (RSGB)
>http://www.ifwtech.co.uk/g3sek
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