98 Tacoma crankshaft pulley holder bolt size

Does any know the bolt size (metric-thread per inch) required to hold down the pulley holder to the crankshaft pulley?. It is way down the third pulley (I did already a trial & error-no luck)and I need to purchase it prior to work. I am changing my timing belt. All I need is the size of the bolt, thats all please.
Thanks....

When I replaced my crankshaft pulley, I needed a new center bolt as well, and the auto parts place knew what size i needed. Just tell them your year and engine size and they will know what you need.

When I replaced my crankshaft pulley, I needed a new center bolt as well, and the auto parts place knew what size i needed. Just tell them your year and engine size and they will know what you need.
I have 1 1998 Tacoma V6 4x4 engine & I plan to replace my timing belt.
Thanks