Hi all. Perhaps already posted years ago but from a foggy memory and poor search skills am revising it.

A magnet M with poles (N /S) has loooong polepieces as parallel iron bars (=======) at each pole.

N=========================================================================E

M

S=========================================================================E

Is the attraction to an iron part placed across the bars near the magnet M , or halfway across the length of the bars, or across the end E showing attenuation according to distance from M ?

-Trying to build a 3 metres long unwanted ferrous scrap picker/collector across a conveyor belt with a magnet at one end and two bars hovering the transported material-

Next... What changes if E and E are joined ( ] ), or, if at the E end of the bars, another equal magnet is attached/implemented (S/N); would the attraction force across bars be doubled ?

Edited January 10Jan 10 by Externet

On 1/10/2026 at 12:34 PM, Externet said:

Hi all. Perhaps already posted years ago but from a foggy memory and poor search skills am revising it.

A magnet M with poles (N /S) has loooong polepieces as parallel iron bars (=======) at each pole.

N=========================================================================E

M

S=========================================================================E

Is the attraction to an iron part placed across the bars near the magnet M , or halfway across the length of the bars, or across the end E showing attenuation according to distance from M ?

-Trying to build a 3 metres long unwanted ferrous scrap picker/collector across a conveyor belt with a magnet at one end and two bars hovering the transported material-

Next... What changes if E and E are joined ( ] ), or, if at the E end of the bars, another equal magnet is attached/implemented (S/N); would the attraction force across bars be doubled ?

Surely you aren't talking about monopole magnets that don't exist? In any case the strongest part of any magnet I am familiar with is always the poles. These guys xxxxxxx sell magnets but their site answers a lot of questions in a fairly concise manner