Thread Mills

Thread Mills

Made in USA since 1992

Which thread do you need?

NPS Pipe Threads
NPS Pipe Threads
UN Threads
UN Threads Unified inch threads, coarse and fine 3, 4 and 5 flute options Best for Standard inch threading, blind or through
UN Threads - Single Form
UN Threads - Single Form
UN Threads - Coolant Through
UN Threads - Coolant Through Same UN threads, coolant fed to the cut Clears chips in deep and blind holes Best for Deep holes and lights-out production
NPT Pipe Threads
NPT Pipe Threads Standard tapered pipe thread Sealed with tape or thread compound Best for General pipe and fitting work
NPTF Pipe Threads
NPTF Pipe Threads Dryseal variant of NPT Crests crush to seal metal-to-metal Best for Hydraulic and fuel lines, no sealant
Metric Threads
Metric Threads ISO metric, multiple pitches per diameter 3, 4 and 5 flute options Best for Metric threading from M4 upward

Thread mills cut internal or external threads using a helical milling path rather than a traditional tap, which reduces the risk of tool breakage in blind holes and hardened materials while allowing one tool to cut multiple thread sizes when paired with the right program. We stock thread mills for UN Threads (including coolant-through versions for improved chip evacuation), NPT Pipe Threads, NPTF Pipe Threads, and Metric Threads.

Because thread milling doesn't rely on axial tap pressure to form threads, it's often the preferred method for hardened steels, thin-walled parts, and large-diameter threads where tapping risks breakage. All thread mills are manufactured in the USA.

  • Compare SKU Vendor Cutter Diameter Thread Size (D1) Shank Diameter (D2) Thread Length (L2) Overall Length (L1) Thread Type Number of Flutes Coating In Stock Price Quantity
    A42765 ACT .245 1/16-27 1/4 .437 2-1/2 NPTF Pipe Thread 3 Uncoated 17
    $185.28
  • A42758 ACT .245 1/16-27 1/4 .437 2-1/2 NPT Pipe Thread 3 Uncoated 70
    $185.28
  • A79017 ACT 0.2400 1/8-27 1/4 0.5700 2-1/2 NPS Pipe Thread 3 ALTiN 100
    $184.67
  • A50081 ACT .245 1/16-27 1/4 .437 2-1/2 NPTF Pipe Thread 3 ALTiN 8
    $192.76
  • A50074 ACT .245 1/16-27 1/4 .437 2-1/2 NPT Pipe Thread 3 ALTiN 28
    $192.76
  • A79018 ACT 0.4300 1/4-18 7/16 0.7370 3 NPS Pipe Thread 4 ALTiN 9
    $246.22
  • A42766 ACT .310 1/8-27 5/16 .437 2-1/2 NPTF Pipe Thread 4 Uncoated 20
    $183.73
  • A42759 ACT .310 1/8-27 5/16 .437 2-1/2 NPT Pipe Thread 4 Uncoated 100
    $183.73
  • A79019 ACT 0.4300 3/8-18 7/16 0.7370 3 NPS Pipe Thread 4 ALTiN 22
    $246.22
  • A71241 ACT .180 1/4-20 3/16 .500 2-1/2 UN Thread Coolant Through 3 ALTiN 14
    $177.45
  • A50082 ACT .310 1/8-27 5/16 .437 2-1/2 NPTF Pipe Thread 4 ALTiN 10
    $193.04
  • A50075 ACT .310 1/8-27 5/16 .437 2-1/2 NPT Pipe Thread 4 ALTiN 66
    $193.04
  • A42767 ACT .370 1/4-18 3/8 .625 3 NPTF Pipe Thread 4 Uncoated 51
    $209.00
  • A42760 ACT .370 1/4-18 3/8 .625 3 NPT Pipe Thread 4 Uncoated 16
    $209.00
  • A50083 ACT .370 1/4-18 3/8 .625 3 NPTF Pipe Thread 4 ALTiN 15
    $219.54
  • A50076 ACT .370 1/4-18 3/8 .625 3 NPT Pipe Thread 4 ALTiN 16
    $219.54
  • A42768 ACT .370 3/8-18 3/8 .625 3 NPTF Pipe Thread 4 Uncoated 20
    $209.00
  • A42761 ACT .370 3/8-18 3/8 .625 3 NPT Pipe Thread 4 Uncoated 100
    $209.00
  • A42748 ACT .240 5/16-18 1/4 .625 2-1/2 UN Thread Coolant Through 3 Uncoated 4
    $211.10
  • A71243 ACT .240 5/16-18 1/4 .625 2-1/2 UN Thread Coolant Through 3 ALTiN 12
    $218.56
  • A50084 ACT .370 3/8-18 3/8 .625 3 NPTF Pipe Thread 4 ALTiN 11
    $219.54
  • A50077 ACT .370 3/8-18 3/8 .625 3 NPT Pipe Thread 4 ALTiN 24
    $219.54
  • A42776 ACT .235 M8 x 0.75 1/4 .625 2-1/2 Metric Thread 3 Uncoated 26
    $185.28
  • A42749 ACT .240 5/16-24 1/4 .625 2-1/2 UN Thread Coolant Through 3 Uncoated 85
    $212.17
  • A71244 ACT .240 5/16-24 1/4 .625 2-1/2 UN Thread Coolant Through 3 ALTiN 25
    $219.64
  • A50092 ACT .235 M8 x 0.75 1/4 .625 2-1/2 Metric Thread 3 ALTiN 10
    $192.76
  • A42777 ACT .235 M8 x 1.00 1/4 .625 2-1/2 Metric Thread 3 Uncoated 38
    $185.28
  • A42750 ACT .290 3/8-16 5/16 .750 3 UN Thread Coolant Through 4 Uncoated 21
    $263.13
  • A50093 ACT .235 M8 x 1.00 1/4 .625 2-1/2 Metric Thread 3 ALTiN 9
    $192.76
  • A42778 ACT .235 M8 x 1.25 1/4 .625 2-1/2 Metric Thread 3 Uncoated 100
    $185.28
  • A42751 ACT .290 3/8-24 5/16 .750 3 UN Thread Coolant Through 4 Uncoated 16
    $263.13
  • A50094 ACT .235 M8 x 1.25 1/4 .625 2-1/2 Metric Thread 3 ALTiN 23
    $192.76
  • A42779 ACT .300 M10 x 1.25 5/16 .750 3 Metric Thread 4 Uncoated 27
    $219.72
  • A71247 ACT .340 7/16-14 3/8 .875 3 UN Thread Coolant Through 4 ALTiN 7
    $228.99
  • A50095 ACT .300 M10 x 1.25 5/16 .750 3 Metric Thread 4 ALTiN 7
    $228.63
  • A42780 ACT .300 M10 x 1.50 5/16 .750 3 Metric Thread 4 Uncoated 100
    $220.74
  • A78991 ACT 0.3880 1/2 1/2 3/4 3 UN Thread 4 Uncoated 58
    $195.22
  • A50096 ACT .300 M10 x 1.50 5/16 .750 3 Metric Thread 4 ALTiN 13
    $229.69
  • A78992 ACT 0.3880 1/2 1/2 1-1/4 3 UN Thread 4 Uncoated 3
    $199.67
  • A42781 ACT .360 M12 x 1.00 3/8 .875 3-1/2 Metric Thread 4 Uncoated 100
    $237.15
  • A42727 ACT .240 5/16-18 1/4 .625 2-1/2 UN Thread 3 Uncoated 100
    $185.28
  • A50097 ACT .360 M12 x 1.00 3/8 .875 3-1/2 Metric Thread 4 ALTiN 18
    $249.11
  • A50056 ACT .240 5/16-18 1/4 .625 2-1/2 UN Thread 3 ALTiN 100
    $192.76
  • A42782 ACT .360 M12 x 1.25 3/8 .875 3-1/2 Metric Thread 4 Uncoated 85
    $237.15
  • A42728 ACT .240 5/16-24 1/4 .625 2-1/2 UN Thread 3 Uncoated 100
    $185.28
  • A50098 ACT .360 M12 x 1.25 3/8 .875 3-1/2 Metric Thread 4 ALTiN 17
    $249.11
  • A50057 ACT .240 5/16-24 1/4 .625 2-1/2 UN Thread 3 ALTiN 22
    $192.76
  • A42783 ACT .360 M12 x 1.75 3/8 .875 3-1/2 Metric Thread 4 Uncoated 38
    $237.15
  • A42729 ACT .290 3/8-16 5/16 .750 3 UN Thread 4 Uncoated 100
    $220.74
  • A50099 ACT .360 M12 x 1.75 3/8 .875 3-1/2 Metric Thread 4 ALTiN 11
    $249.11
  • A50058 ACT .290 3/8-16 5/16 .750 3 UN Thread 4 ALTiN 100
    $229.69
  • A42784 ACT .360 M14 x 1.50 3/8 .875 3-1/2 Metric Thread 4 Uncoated 28
    $237.15
  • A42730 ACT .290 3/8-24 5/16 .750 3 UN Thread 4 Uncoated 100
    $220.74
  • A50100 ACT .360 M14 x 1.50 3/8 .875 3-1/2 Metric Thread 4 ALTiN 13
    $249.11
  • A50059 ACT .290 3/8-24 5/16 .750 3 UN Thread 4 ALTiN 43
    $229.69
  • A42731 ACT .340 7/16-14 3/8 .875 3 UN Thread 4 Uncoated 100
    $237.03
  • A50060 ACT .340 7/16-14 3/8 .875 3 UN Thread 4 ALTiN 30
    $247.67
  • A42732 ACT .340 7/16-20 3/8 .875 3 UN Thread 4 Uncoated 100
    $237.03
  • A50061 ACT .340 7/16-20 3/8 .875 3 UN Thread 4 ALTiN 20
    $247.67
  • A42733 ACT .350 1/2-13 3/8 .875 3-1/2 UN Thread 4 Uncoated 100
    $236.13
  • A50062 ACT .350 1/2-13 3/8 .875 3-1/2 UN Thread 4 ALTiN 45
    $247.50
  • A42734 ACT .350 1/2-20 3/8 .875 3-1/2 UN Thread 4 Uncoated 69
    $236.13
  • A50063 ACT .350 1/2-20 3/8 .875 3-1/2 UN Thread 4 ALTiN 49
    $247.50
  • A79012 ACT 0.3880 1/2 1/2 3/4 3 UN Thread 4 ALTiN 18
    $212.55
  • A79013 ACT 0.3880 1/2 1/2 1-1/4 3 UN Thread 4 ALTiN 13
    $217.69
  • Total: items /

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