Scrap carbide inserts, every corner used up

An insert is a small, replaceable cutting tip clamped into a steel holder. University machining slides (2010 textbook) call inserts cutting tools with several cutting points: 8 on a square insert, 6 on a triangular one. When one edge is worn, the insert is indexed: rotated in its holder so a fresh point takes the cut. ITIA, the tungsten industry association, says inserts are used for turning, milling, grooving, threading and drilling, and one tool body can carry up to 300 of them.

A tool-wear course lecture names the ways a corner gives out: flank wear (a land rubbed into the edge), crater wear (wear on the top face of the tool), notch wear and heat-shock cracks. ISO 3685:1993, as cited in a University of Mons paper, counts an insert as finished once it stops making parts of the desired size and surface quality. When every corner gets there, the insert is scrap, and that is when we want it.

Small as it is, an insert is mostly tungsten. ITIA writes that "the percentage of tungsten in the inserts is very high", typically above 80%.

Sources: King Saud University cutting tool slides (2010 textbook); ITIA, Cemented carbides (June 2010 newsletter excerpt); AASTMT course IM212, Tool Wear - Tool Life (2017); University of Mons, Materials Science Forum vol. 986 (cites ISO 3685:1993); ITIA, recycling newsletter excerpt (May 2018).

University lecture notes describe two ways a carbide tip is fixed to its tool: mechanical clamping, or brazing to the shank. Clamped inserts are the easy case. An ITIA diagram labels the tool holder steel and the screwed-on insert 100% hardmetal, easy to separate.

So take them apart first. Pull the holder, screws and clamps out of the lot; they add weight without adding carbide. Zeiler and co-authors describe what happens otherwise: a worn drill head that is mostly steel can land in a steel scrap tray, where its tungsten and cobalt are diluted and lost.

A tip brazed onto a shank will not unscrew, so leave those whole and bag them with your brazed tools and saw tips. Wipe off heavy oil and let wet inserts dry: USGS notes the zinc recycling process does not purify, so sorting and removing oil come first.

Sources: King Saud University metal cutting lecture (2010 textbook); ITIA, recycling newsletter excerpt (May 2018); Zeiler et al. 2021, Tungsten recycling (open access, ITIA copy); USGS Open-File Report 01-349.

Pick Inserts on the quote form, give a rough weight, and add two or three photos: the whole lot, plus a close-up of a handful spread out on a bench. Note any bag of look-alikes. Email works as well, at help@carbidebuyersusa.com, or call (877) 899-5778.

From any state in the US you can ship the lot to us, and we pay the shipping (see the shipping page). In every city in California, Arizona, Utah and Nevada we can come to you and pick it up instead. We are a family owned and operated business that buys scrap carbide in any form, and we pay cash where state law allows; our state law guide sets out what each state asks of a seller.