Removing Bicycle Pedals

I just received automatic SPD pedals for my bike. I do not have this special tool to remove / install the pedals. What is the key size (standard / metric) can I use to replace that special tool?

Yes I agree most of the pedal keys, 15mm, but 9 times out of 10 with a 15mm wrench will not fit for use on a pedal application. Even if the size is just the thickness key will not allow the application of the standard key. I can tell you this because I use Shimano SPD and the standard key (not suitable.) Pedal keys are much thinner. If your pedals have extended a pin wrench can agree, this is the only way. The pedal wrench, you will cost as little as $ 13.99 and perhaps cheaper. visit the website below. There are five listed, I would also check to a bike shop to see if maybe the prices are cheaper.

Most pedals use a wrench 15 mm. Sometimes they have an Allen key hole at the end of the pedal which is 8 mm. The left rudder left handed threads if you put them clockwise to remove. Stand on the bike and the pedal position to obtain maximum leverage.

http://bicycletutor.com/replace-pedals/

Most pedals use a 15mm wrench.
Some may also use an Allen wrench on the end of the axle.
Remember the left side of the bike, son of his left hand, right side of the bike, son of RIGHT hand.

15mm usually works fine, do not forget to reverse the son when removing and setting.