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ANSI Thread Series Designations

Designations

Thread Series

ANSI Reference

ACME-C

Acme Threads, centralizing

B1.5

ACME-G

Acme threads, general purpose (see also Stub Acme)

B1.5

AMO

American Standard microscope objective threads

B1.11

ANPT

Aeronautical National Form taper pipe threads (2)

. . .

BUTT

Buttress threads, pull type

B1.9

PUSH-BUTT

Buttress threads, push type

B1.9

F-PTF

Dryseal fine taper pipe thread series

B1.20.3 (Appendix C)

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


Class 5 interference fit external threads

 

NC5HF

For driving in hard ferrous material of hardness over 160 Bhn

B1.21M

NC5 CSF

For driving in copper alloy and soft ferrous material of 160 Bhn or less

B1.21M

NC5 ONF

For driving in other nonferrous material (Nonferrous materials other than copper alloys), any hardness

B1.21M


Class 5 interference fit internal threads

 

NC5 IF

Entire ferrous material range

B1.21M

NC5 INF

Entire nonferrous material range

B1.21M

NGO

National gas outlet threads (1)

ANSI/CGA V-1 (B57.1)

NGS

National gas straight threads

ANSI/CGA V-1 (B57.1)

NGT

National gas taper threads (see also SGT)

ANSI/CGA-V1 (B57.1)

NH

American Standard hose coupling threads of full form

(B1.20.7)

NHR

American Standard hose coupling threads for garden hose applications

B1.20.7

NPSC

American Standard Straight pipe threads in pipe couplings

B1.20.1

NPSF

Dryseal American Standard fuel internal straight pipe threads

B1.20.3

NPSH

American Standard straight hose coupling threads for joining to American Standard taper pipe threads

B1.20.7

NPSI

Dryseal American Standard intermediate internal straight pipe threads

B1.20.3

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

NPT

American Standard taper pipe threads for general use

B1.20.1

NPTF

Dryseal American Standard taper pipe threads

B1.20.3

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)

S

ISO miniature screw threads .25 to 1.4mm, inclusive

. . .

SGT

Special gas taper threads (ANSI/CGA V-1)

B57.1

SPL-PTF

Dryseal special taper pipe threads

B1.20.3 (Appendix C)

Stub Acme

Stub Acme threads

B1.8

UN

Unified inch screw thread, constant-pitch series

B1.1

UNF

Unified inch screw thread, fine-pitch series

B1.1

UNEF

Unified inch screw thread, extra-fine pitch series

B1.1

UNJ

Unified inch screw thread, constant-pitch series, with rounded root of radius 0.15011P to 0.18042P

 

UNJC

Unified inch screw thread, coarse-pitch series, with rounded root of radius 0.15011P to 0.18042P

B1.15

UNJF

Unified inch screw thread, fine-pitch series, with rounded root of radius 0.15011P to 0.18042P

B1.15

UNJEF

Unified inch screw thread, extra-fine pitch series, with rounded root of radius 0.15011P to 0.18042P

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-thread 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

B1.1

UNREF

Unified inch screw thread, extra-fine pitch series, with rounded root of radius not less than 0.108P

B1.1

UNM

Unified miniature thread series

B1.10

UNS

Unified inch screw thread, special diameter pitch or length of engagement

B1.1

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 SAE A571051

 

 

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