What is edge trimming scrap metal and how is it produced?
Edge trimming scrap metal is the scrap recovered from hot rolled coil slitting. There are many different names for this type of scrap metal which has no clear classification with ISRI – the institute of scrap recycling industries.
The nearest official classification for trimming bundles would be:
“No. 1 bundles may include stanley balls or mandrel wound bundles or skeleton reels.” However, even then it goes nowhere near to correctly classifying what HR trimming scrap is and its specification.
Other names edge trimming is known as including hot-rolled (HR) side-cutting scrap, mandrel wound bundles, trimming, slitter scrap & bobbin bundles.
How edge trimming is produced
Firstly, let’s look at how this type of scrap is produced. Large hot-rolled coils are loaded onto a coil slitting production line to make the coils smaller in size and meet specific user requirements. The coil is loaded and then unwound. It is then straightened on the production line and slit. This slitting process creates an excess scrap metal known as edge trimming.
Most slitting lines will have either a scrap baller/ winder or a scrap cutting tool. The first will form the strip scrap from the slitting process into a wound ball, the latter chopping it into pieces. The aim of both tools is to make the scrap metal easy to manage, but the end uses and recycling of both can differ greatly.
The chopped scrap metal would be only be used as melting scrap. However, the wound trimming, if meeting the right specification, can be re-used in new wire manufacture without the need to melt it, making it the more environmentally friendly and efficient means to recycle it.
While there is clearly a grey area in finding an officially recognised actual definition for edge trimming scrap metal, the buyer and seller should agree on the specification before prior to finalising any trade between them.