Taz 4 Hardened Steel Hobbed Bolt

I’m looking into printing carbon fiber with my Taz 4. I’m planning on using an Olsson Ruby nozzle but it was recommended that I also change to a hardened steel hobbed bolt. Can anyone suggest a non-sketchy vendor where I could find this bolt? I found a couple but reliability of the sites was questionable at best.

Thanks!

Find one with these dimensions and you’ll be a bit more confident in your selection. You can always replace the hobbed bolt with the standard one if your new one isn’t to your liking: http://download.lulzbot.com/retail_parts/Completed_Parts/Hobbed_Bolt_50mm_KT-CP0098/Hobbed_bolt_26.PDF