hex driver
Hex Drivers for the HK450 Helicopter
I use the 1.5mm Hex Driver and the 2.0mm Hex Driver 2.0mm not used often at all

Why did I pay so much for a hex driver? Well actually I got the 1.5mm from above and another 1.5mm & 2.0mm from a local hardware.
Well the simple fact is I destroyed so many bolts and hex drivers, these ones are hardened steel, you could source them locally at a hobby shop, and it will probably be cheaper because these add weight to shipping being solid alloy handles.
But make sure you get a really good set, you need them to be brittle strong, no bendable, they must be toughened or hardened steel. They need to look like a drill bit does when they snap. Explain that to the local hardware and he will point you to the more expensive hex drivers. Last thing you want is to strip a head on a bolt that goes in through your blade grips to the feathering shaft, any way you look at it that repair is going to cost you a lot more than a hex driver will.
So Again,
MAKE SURE THEY ARE THE BEST YOU CAN GET
Regards
Elias Gourvelos (EatAtJoes)