Why Not Carbide Material For Broaches?

We run across this question often from potential customers, especially when trying to rotary broach in a tough medical grade alloy above 30 Hrc such as Custom 455, 17-4 H900, Titanium, or BioDur materials. Finding a Broach tool with perfect blend of wear resistance and toughness is key. Carbide has greater wear resistance than HSS or HiCo HSS, but has much less toughness. Carbide is great for turning and milling operations and can hold it’s hardness when high heat is involved because of its high Cobalt content. In Rotary and Push broaching operations there is very little heat generated, so there is no benefit for a broach with HiCo content. HSS’s toughness comes into play in rotary and punch style broaching. These operations cause Carbide to chip or micro chip, yielding poor tool life. Micro chipping can often look like premature tool wear, but is actually many tiny chips.

This is where applying the Rayco Heat Treat Process to HSS can bridge this gap. Our process creates a finer grain structure at a higher hardness, while maintaining the toughness. Conventional Heat Treated HSS creates this fine structure, but at a lower hardness, therefore lacking the wear resistance compared to a Rayco Heat Treated Broach. And this process we have been using since 1947. It’s a proven process

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