Mutagen vs Carcinogen Mutagen and carcinogen are two terms that have a lot in common. There is a potential that a single substance could be both of them at the same time and be only one of the two, as well.
A curb bit is a type of bit used for riding horses that uses lever action. It includes the pelham bit and the Weymouth curb along with the traditional curb bit used mainly by Western riders. Kimblewicks or Kimberwickes are modified curb bits, and a curb bit is used in a double bridle along with a bradoon.
1 Flush trim router -- This type of bit has a giveaway name. They are used to make the edge of one material flush with another, like trim.  Joinery bits - These bits can be found in just about any shape and size, making them perfect for joining two separate materials together.