Threading Taps



  • Available in Bearing Steel and HSS
  • Used for cutting internal threads in pre-determined holes.
  • Provided in sets of 3:
    • Taper Tap: For through holes or for starting blind holes
    • Plug Tap: For through holes or for getting closer to the bottom of blind holes
    • Bottom Tap: For cutting threads at the bottom of a blind hole.
Threading Taps

55-58º HRC - Carbon Steel

Carbon Steel / HSS


Types of taps

Taps are used to cut screw threads in pre determined bores and come in a large range of sizes and thread profiles. Depending upon the usage the threading taps are divided into three categories:

  • TAPER TAP
    • 8 to 9 chamfered threads.
    • Gradually cuts material in succession throughout its length of the partial threads.
    • Used for through holes or as a starting tap for blind hole.
  • PLUG TAP
    • 4 to 5 chamfered threads.
    • Can be used without a starter tap for through holes.
    • Used to getting closer to the bottom of a blind hole.
  • BOTTOM TAP
    • 1 to 1.5 chamfered threads
    • Used for cutting threads at the bottom of a blind hole.
    • Used after the application of taper and plug taps

 

 

 

Threading a bore using a tap

Determine the bore size required for the desired thread using a tap-drill size chart. The length of the bore should be slightly greater than the required length of the thread. 

Once the bore is drilledgrip the tap's square shank between the jaws of the Adjustable tap wrench. For components with confined spaces inaccessible to an adjustable wrench, T-tap wrenches can be used. Make sure that the hole is properly lubricated before beginning the operation.

Align the axis of the tap with that of the bore before it enters into the material. Misaligned taps call for excessive force and not only tampers the component but can also break the tap itself. Once everything is in order rotate the tap into the bore. It is a good practice to rotate the tap a quarter turn back after every half a turn into the material. This prevents the tap from clogging in the bore by breaking and removing the chips thus ensuring cleaner threads and longer tap life.

 

 

 

Tap-Drill size chart

BSF,UNF,UNC,METRIC,BSW,BSP,BSB,NPT,BSPT,ME,BA,and special sizes  

C.No Nominal Size (inch) action
TAP-0116I 1/16
TAP-0332I 3/32
TAP0180I 1/8
TAP-0532I 5/32
TAPI-0316I 3/16
TAPI-0732I 7/32
TAP-Q 1/4
TAP-0932I 9/32
TAP-0516I 5/16
TAP-0380I 3/8
TAP-0716I 7/16
TAP-Q2 1/2
TAP-0916I 9/16
TAP-0580I 5/8
TAP-1116I 11/16
TAP-Q3 3/4
TAP-1316I 13/16
TAP-0780I 7/8
TAP-1516I 15/16
TAP-1I 1
TAP-1-0180I 1-1/8
TAP-1Q 1-1/4
TAP-1-0380I 1-3/8
TAP-1Q2 1-1/2
TAP-1Q3 1-3/4
TAP-2 2

 

Metric Sizes

C.No Nominal Size (mm) Pitch (mm) action
TAP-2M 2 0.4
TAP-3M 3 0.5
TAP-4M 4 0.7
TAP-5M 5 0.8
TAP-6M 6 1.0
TAP-7M 7 1.0
TAP-8M 8 1.25
TAP-9M 9 1.25
TAP-10M 10 1.50
TAP-11M 11 1.50
TAP-12M 12 1.75
TAP-14M 14 2.0
TAP-16M 16 2.0
TAP-18M 18 2.5
TAP-20M 20 2.5
TAP-22M 22 2.5
TAP-24M 24 3.0
TAP-27M 27 3.0
TAP-30M 30 3.5