pipe

(slang) something regarded as easy to accomplish. From lead-pipe cinch: a doubly sure or doubly easy thing. Lead pipe refers to a Midwestern and Western US form of galvanized iron pipe (which looks as if it were lead). For saddling and cinching (fixing a saddle securely) the sort of horse that expands its belly, a short length of this so-called lead pipe was slipped under the saddle strap and turned like a tourniquet, the work assisted by a few knee jabs in the belly. Thus the horse was forced to deflate and the saddle was cinched tight, that horse now being double (lead-pipe) cinched.