There are various types of UN thread taps, and knowing on time when to use each kind is the goal of this write-up

1. WHAT ARE THE DIFFERENT TYPES OF TAPS
There are varioustypesof UN threadtaps,and knowingontime whentouse eachkindis the goal of this
write-up
A greatrange of UN threadtapsare available withvaryingadvantagesanddisadvantages:
1. Hand Taps (Tap SetTaps, StraightFlute Taps)
Hand taps,boughtat the local hardware store,are the most commontypesof taps, buttheyare
generallytobe avoidedforCNCwork.
Try and buysome good qualitytapsandtry out tappingbyhand versusthe hardware store setof thread
taps.You’ll be amazedat howmuch bettertapsare made for machineswork.
One suitable standardforHandTaps is ISO529.
There are twotypesof Hand Taps:
Taper Tap
A tapertap has quite a lotof taper to helpitease intocuttingthreadsgradually.Commonly,the first8
to 10 threadsare usuallytapered. TaperTaps are the mostcommontypesof UN thread taps and are
commonlywhatyou’ll have inaTap and Die Set.
BottomingTap
A bottomingtaphas almostnotaper at the endat all because itis designedandcreatedtothreadall the
wayto the bottomof its reach. Just 1 to 1.5 threadswill be tapered.
BottomingTapsare quite useful forthreadingblindholes. It’sdesirabletothreadmostof the hole with
a Taper Tap first,and thenfinishthe bottomof the hole withaBottomingTap.
2. PlugTap
PlugTaps are inbetweenTaperTapsandbottomingbecause theyhave 3-5threadstapered,whichis
more than a BottomingTap and lessthana Taper Tap.
3. Spiral PointTaps (GunNose or Bull Nose Taps)
These threadtapshave a spiral cutwithrelief grooves.They’re commonandlooklike mostof the hand
taps you’ll see around,butthe spiral angle atthe frontcuttingedges helpsremove the chipsandthe
anglededge alsogivescuttingpowerthatissuperior. Hence,they’re reallythe leastexpensive UN
threadtap youmightuse for powertapping,anditcan be run at slightlyhigherspeedsthanhandtaps.

2. Like handtaps, spiral pointtapscan be had as a tapertap has a taperedend,ora plugtap haslesstaper.
The cost is cheapcomparedto the othertwo typesbutthe two are both preferred.The primary
disadvantage of these istheypushthe chipsaheadof the tap–downintothe hole inotherwords.Thisis
not a bigdeal for throughholesbutisa bad ideafor blindholes.
4. Spiral Flute Tapsor Gun Taps
Spiral Flute Tapshave an openspiral justlike anendmill.Theirprimaryadvantage istheyejectchipsup
and outof the hole.
They’re alsochosenforan interruptedholewhere anotherfeature intersectsbecause the spiralhelpsin
restartingthe threadingpastthe openfeature.
Sometimes,take aspiral flute tapanda regularhandtap and tap a couple of identical holesby hand.
You’ll be amazedat howmuch lesseffortthe spiral flute tapneeds. Choosingthe righttypesof UN
thread tap reallyhelps!
5. InterruptedThreadTap
These UN threadtaps onlyhave a toothfor everyotherthread. The ideaisto ensure improvedchip
extraction. Removingeveryothertoothhelpsinbreakingchipsandalsoprovidesmore roomforthe
chipto escape and forlubricantto come inand do itsjob.