How much should I overclock my i5 6600k

[Carnivorex2]

https://www.amazon.com/Intel-Skylake-Desktop-Processor-BX80662I56600K/dp/B012M8M7TY/ref=sr_1_1?ie=UTF8&qid=1510510484&sr=8-1&keywords=i5+6600k+processor

i5 6600k 3.5 GHz

I have good coolers

Can someone tell me what I should safely overclock to (GHz)
And also tell me how much voltage I should use.
Any additional information would be great thanks.

 

[OCD Tweaker]

my i5 6600k
is at 4.7ghz at 1.345V
idles 28c under 100% load with p95 45c steady after 4 hours

i am also water cooling with a 360mm slim rad and a 120 rad

basically your chip might not be able to reach what mine will nor mine with some one else's (SILICON LOTTERY)

if your going to OC dont go past 1.3v
you can easily probably hit 4.2 or 4.4ghz with out increasing your volts. BUT it comes down to if you are adequately cooling your CPU
when you OC your CPU its going to get hotter so you have get cool it faster or it becomes damaged

 

[DarkOutlaw]

I think you should take some time and read about overclocking. These are basic questions covered by any overclock guide on the web. Do your research, and use google. I feel that both of you don't really know too much about overclocking.