Since its launch in late 2017, Intel hasn’t grown the Coffee Lake platform beyond the initial set of products. That’s apparently about to change with the release of three new CPUs: The i5-8600, i5-8500, and i3-8300 have been listed on online retailer Provantage, although you can't yet buy them.
These are all “non-K” parts, so they don’t have an unlocked multiplier for easy overclocking on a Z370 motherboard, but they’re likely meant to be paired with the upcoming budget-oriented H370 and B360 boards. Relative to the current lineup of Coffee Lake CPUs, the i5-8600 will slot in below the i5-8600K. The i5-8500 will be under that, and the i3-8300 will be below the i3-8350K.
The i5-8600 maintains similar specs to its unlocked counterpart, including the 9MB of cache and 4.3GHz max boost clock, but it trades overclocking and possibly some loss in base frequency for a lower price ($217 vs. $251 on Provantage). The i5-8500 appears to be just a downclocked version of the 8600. For its lower max boost clock of 4.1GHz (and probably lower base frequency too), there is a slight savings ($199 on Provantage). It appears to be the same case for the i3-8300 when it’s compared to the i3-8350K. For a locked clock multiplier and a lower base frequency (3.7GHz vs 4.0GHz), it has a lower price ($135 on Provantage vs. $168 MSRP).
Provantage also lists “T” versions of all of these processors for bulk purchase. For previous Intel CPU lines, like Skylake, the “T” versions were even further downclocked versions of the regular “non-K” parts, intended for applications that require lower power and heat. The i5-8600T is listed with a max boost clock of 3.7GHz, the i5-8500T with 3.5GHz, and the i3-8300 with base frequency of 3.2GHz.