ANSI and International Thread Series Designations

Thread Check Inc. manufactures gages to the following ANSI Thread Series Designations:

Designations Thread Series Reference
UN Unified Inch Screw Thread, Constant-Pitch Series B1.1
UNC Unified Inch Screw Thread, Coarse-Pitch Series B1.1
UNF Unified Inch Screw Thread, Fine-Pitch Series B1.1
UNEF Unified Inch Screw Thread, Extra-Fine Series B1.1
UNS Unified Inch Screw Thread, Special Diameter Pitch, or Length of Engagement B1.1
UNJ Unified Inch Screw Thread, Constant-Pitch Series with Rounded Root of Radius 0.15011P to 0.18042P (3) B1.15
UNJC Unified Inch Screw Thread, Coarse-Pitch Series, with Rounded Root of Radius 0.15011P to 0.18042P (3) B1.15
UNJF Unified Inch Screw Thread, Fine-Pitch Series, with Rounded Root of Radius 0.15011P to 0.18042P (3) B1.15
UNJEF Unified Inch Screw Thread, Extra-Fine Pitch Series, with Rounded Root of Radius 0.15011P to 0.18042P (3) B1.15
UNR Unified Inch Screw Thread, Constant-Pitch Series, with Rounded Root of Radius Not Less Than 0.108P B1.1
UNRC Unified Inch Screw Thread, Coarse-Pitch Series, with Rounded Root of Radius Not Less Than 0.108P B1.1
UNRF Unified Inch Screw Thread, Fine-Pitch Series, with Rounded Root of Radius Not Less Than 0.108P B1.1
UNREF Unified Inch Screw Thread, Extra-Fine Pitch Series, with Rounded Root of Radius Not Less Than 0.108P B1.1
NC5 Class 5 Interference Fit External Threads B1.12
NC5HF For Driving in Hard Ferrous Material of Hardness over 160 Bhn B1.12
NC5CSF For Driving Copper Alloy and Soft Ferrous Material of 160 Bhn or Less B1.12
NC5ONF For Driving in Other NonFerrous Material (Nonferrous Materials Other Than Copper Alloys, Any Hardness B1.12
NC5 Class 5 Interference Fit Internal Threads B1.12
NC5 IF Entire Ferrous Material Range B1.12
NC5 INF Entire Nonferrous Material Range B1.12
M Metric Screw Threads-M Profile with Basic ISO 68 Profile B1.13M B1.18M
MJ Metric Screw Threads-MJ Profile with Rounded Root of Radius 0.15011P to 0.18042P B1.21M
MJS Metric Screw Threads-MJ Profile Special Series B1.21M
UNM Unified Miniature Thread Series B1.10
NPT American Standard Taper Pipe Threads for General Use B1.20.3
NPTF Dryseal American Standard Taper Pipe Threads B1.20.3B
F-PTF Dryseal Fine Taper Threads Series B1.20.3 Appendix.C
PTF-SAE Short Dryseal SAE Short Taper Pipe Threads B1.20.3
PTF-SPL Short Dryseal Special Short Taper Pipe Threads B1.20.3 Appendix.C
PTF-SPL Extra Short Dryseal Special Short Taper Pipe Threads B1.20.3 Appendix.C
SPL-PTF Dryseal Special Taper Pipe Threads B1.20.3 Appendix.C
ANPT Aeronautical National Form Taper Pipe Threads (2) MIL P-7105B
NPSL American Standard Straight Pipe Threads for Loose-Fitting Mechanical Joints with Locknuts B1.20.1
NPSM American Standard Straight Pipe Threads for Free-Fitting Mechanical Joints for Fixtures B1.20.1
NPSC American Standard Straight Pipe Threads in Pipe Couplings B1.20.1
NPSF Dryseal American Standard Fuel Internal Straight Pipe Threads B1.20.3
NPSI Dryseal American Standard Intermediate Internal Straight Pipe Threads B1.20.3
NH American Standard Hose Coupling Threads of Full Form B1.20.7
NPSH Dryseal American Standard for Hose Coupling Joints with Straight Internal & External Loose Fitting Threads B1.20.7
NFPA 1963 Fire Hose Connections ­­­­­
NHR American Standard Hose Coupling Threads for Garden Hose Applications B1.20.7
NGT National Gas Taper Threads (See Also SGT) CGA V-1
NGO National Gas Outlet Threads (1) CGA V-1
NGS National Gas Straight Threads CGA V-1
SGT Special Gage Taper Threads BS.21
R British Taper Pipe Threads BS.21
Rc, Rp British Taper Pipe Threads BS.21
G Straight Pipe Threads BS.2779
BSW British Parallel Screw Threads BS.84
BSF British Parallel Screw Threads BS.84
BA British Screw Threads BS.57
ACME-C Acme Threads, Centralizing B1.5
ACME-G Acme Threads, General Purpose B1.5
STUB ACME Stub Acme Threads B1.8
BUTT Buttress Threads, Pull Type B1.9
PUSH-BUTT Buttress Threads , Push Type B1.9
AMO American Standard Microscope Objective Threads B1.11
AWWA Underground Service Line Valves and Fittings C800-84
DIN German Specifications ­­­­­
JIS Japanese Industrial Standard ­­­­­
ISO International Standard Organization ­­­­­

NOTES:

  1. All threads, except NGO, are right hand, unless otherwise designated. For NGO threads, designations RH or LH are required.
  2. As published in Military Specification MIL-P7105
  3. As published in Military Specification MIL-S8879, and ISO 3161
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