“Solid Die “ or “ Hollow Die” you may well hear your supplier use these terms.
No, of course, they are not referring to a solid Die with no holes in it, they are referring to the configuration of the die and the type of extrusion being produced from it.
A solid Die is a die which will produce an extrusion with no complete tubes in it or as they will describe it “No Hollows”, A screw port in an extrusion is the shape of a ‘C’ which forms a location and material to be screwed into without being a complete hollow.
It is good to remember that a solid die will invariably cost less than a Hollow die.
Hollow Die Yes that’s right it is a die which will produce an extrusion with Hollows in it, the extrusion could be a tube round, oval, Square or just have pockets of irregular shape within the extrusion.
This die is more complex and will cost more money usually, as the Die must incorporate the centre plug of metal which will form the void for the tube, obviously this centre must be held in place firmly with legs ,the aluminium must then flow around the legs and re-form the wall of the hollow before leaving the die.
The more hollows in the extrusion the more complex the die.
Where the aluminium reforms in the die it is known as the weld line and although the aluminium is structurally sound at this point if anodising the extrusion you may see a difference with a coloured finish as the crystalline structure will not be consistent with the rest of the extrusion.
A point worth considering when looking for aesthetics from the finished product.