Crank bolt sizes

[astro]

Hi, bit of a newbie to bike repair. I'm looking to change the front gears on my mountain bike. I've got the correct crank pulling tool, unfortunately I don't have the correct socket to remove the crank bolt. The bolt is bigger than the 14mm socket but smaller than the 17mm. Are there standard sizes of crank bolts (this is a Shimano gear-set, bike bought in the Netherlands, roughly 5-10 years old)? If so what is the most likely size I'll need to buy?

[Joe_W]

OK, if the crank set is Shimano, then the removing tool will fit the cranks (but not necessarily the bolt... been there). The bolt could be 15mm or 16mm, a regular 16mm nut will not fit inside the hole in the crank. The tool to remove small spark plugs could fit (it is 16mm), it did for me. Some bike shops have 15mm and 16mm nuts that are turned down to fit inside the crank hole.