Trying to purchase the correct handlebar faceplate bolt in advance for Schwinn S2713TR
You really need to take the remaining bolt to the hardware store and get them to match something with the appropriate length and thread pitch. 

This isn't a standard length or size, but its likely M5 or M6 with length somewhere between 15-25 mm. You'd probably end up buying at least 6-8 packs of bolts to find the right one without measuring the existing one.