Editing Tap and die (section)

{{Short description|Tools to create screw threads}}
{{distinguish |text= [[Tool and die maker|Tool and die]]}}
{{multiple image
 | width = 120
 | image1 = Tap and T-wrench.jpg
 | alt1 = Tap in a wrench
 | image2 = Schneideisen.jpg
 | alt2 = Die in a wrench
 | footer = Tap in a wrench for creating female [[screw thread|threads]] (left), and die in a wrench for creating male threads (right).
}}
'''Taps''' and '''dies''' are tools used to create [[screw thread]]s, which is called [[threading (manufacturing)|threading]]. Many are [[cutting tool]]s; others are forming tools. A tap is used to cut or form the [[gender of connectors and fasteners|female]] portion of the mating pair (e.g. a [[nut (hardware)|nut]]). A die is used to cut or form the male portion of the mating pair (e.g. a [[bolt (fastener)|bolt]]). The process of cutting or forming threads using a tap is called ''tapping'', whereas the process using a die is called ''threading''.

Both tools can be used to clean up a thread, which is called ''chasing''. However, using an ordinary tap or die to clean threads generally removes some material, which results in looser, weaker threads. Because of this, machinists generally clean threads with special taps and dies—called ''[[Thread restorer|chasers]]''—made for that purpose. Chasers are made of softer materials and don't cut new threads. However they still fit tighter than actual fasteners, and are fluted like regular taps and dies so debris can escape. Car mechanics, for example, use chasers on spark plug threads, to remove corrosion and carbon build-up.