I've recently tried a cheap MGEHR1212-2 insert carbide parting tool off eBay and it actually works good with 1" rounds of tool steel on my 12x36. Better than my usual M42 parting blade set up. I can only imagine that the name brand insert parting tools are even better, but the $16 tool is surprisingly a great value. Its cheaper than a single Shars parting blade shipped. I can power through hard and get a decent parting, the inserts are lasting better than expected.