| STANDARD TAP MARKING |
PRODUCT THREAD DESIGNATION |
THREAD SERIES |
REFERENCES AMERICAN NATIONAL STANDARDS (ANSI/ASME) |
| ACME-C |
ACME-C |
Acme threads, centralizing |
B1.5 |
| ACME-G |
ACME-G |
Acme thread, general purpose (See also STUB ACME) |
B1.5 |
| AMO |
AMO |
American Standard microscope objective threads |
B1.11 |
| NPT |
ANPT |
Aeronautical National Form taper pipe threads |
(MIL-P-7105B) |
| BUTT |
BUTT |
Buttress Threads, pull type |
B1.9 |
| PUSH-BUTT |
PUSH-BUTT |
Buttress Threads, push type |
B1.9 |
| F-PTF |
F-PTF |
Dryseal fine taper pipe thread series |
B1.20.3 (Appendix C) |
| M |
M |
Metric Screw Threads - M Profile with basic ISO 68 profile |
B1.13M, B1.18M |
| MJ |
MJ |
Metric Screw Threads - MJ Profile with rounded root of radius 0.15011P to 0.18042P |
B1.21M |
| MJS |
MJS |
Metric Screw Threads - MJ Profile, special series Class 5 interference fit Internal Threads |
B1.12 |
| NC |
NC5IF |
Entire ferrous material range |
|
| NC |
NC5INF |
Entire nonferrous material range |
|
| NGO (RH or LH) |
NGO |
National gas outlet threads |
ANSI/CGA V-1 (B57.1) |
| NGS |
NGS |
National gas straight threads |
ANSI/CGA V-1 (B57.1) |
| NGT |
NGT |
National gas taper threads |
ANSI/CGA V-1 (B57.1) |
| NH |
NH |
American Standard hose coupling threads of full form |
B2.4 |
| NPS |
NPSC |
American Standard straight pipe threads in pipe couplings |
B1.20.1 |
| NPSF |
NPSF |
Dryseal American Standard fuel internal straight pipe threads |
B1.20.3 |
| NPSH |
NPSH |
American Standard straight hose coupling threads for joining to American Standard taper pipe
threads |
B2.4 |
| NPSI |
NPSI |
Dryseal American Standard intermediate internal straight pipe threads |
B1.20.3 |
| NPSL |
NPSL |
American Standard straight pipe threads for loose-fitting mechanical joints with locknuts |
B1.20.1 |
| NPS |
NPSM |
American Standard straight pipe threads for free-fitting mechanical joints for fixtures |
B1.20.2 |
| NPT |
NPT |
American Standard taper pipe threads for general use |
B1.20.1 |
| NPTF |
NPTF |
Dryseal American Standard taper pipe threads |
B1.20.3 |
| NPTR |
NPTR |
American Standard taper pipe threads for railing joints |
B1.20.1 |
| PTF SHORT |
PTF-SAE SHORT |
Dryseal SAE short taper pipe threads |
B1.20.3 |
| PTF SPL SHORT |
PTF-SPL SHORT |
Dryseal special short taper pipe threads |
B1.20.3 (Appendix C) |
| PTF SPL |
PTF-SPL EXTRA |
|
|
| X-SHORT |
SHORT |
Dryseal special extra short taper threads (See also SPL-PTF) |
B1.20.3 (Appendix C) |
| M |
S |
ISO Miniature screw threads 0.25 to 1.4mm inc. |
|
| SGT |
SGT |
Special gas taper threads |
ANSI/CGA V-1 (B57.1) |
| SPL-PTF |
SPL-PTF |
Dryseal special taper pipe threads |
B1.20.3 (Appendix C) |
| STUB ACME |
STUB ACME |
Stub Acme threads |
B1.8 |
| STUB ACME M1 |
STUB ACME M1 |
Stub Acme Modified Form 1 |
B1.8 |
| STUB ACME M2 |
STUB ACME M2 |
Stub Acme Modified Form 2 |
B1.8 |
| N |
UN |
Unified inch screw thread, constant-pitch series |
B1.1 |
| NC |
UNC |
Unified inch screw thread, coarse-pitch series |
B1.1 |
| NF |
UNF |
Unified inch screw threwd, fine-pitch series |
B1.1 |
| NEF |
UNEF |
Unified inch screw thread, extra-fine pitch series |
B1.1 |
| N |
UNJ |
Unified inch screw thread, constant-pitch series, with rounded root of radius 0.15011P to
0.18042P. (Ext. thd. only) |
B1.15 (Draft) MIL-S-8879A |
| NC |
UNJC |
Unified inch screw thread, coarse-pitch series, with rounded root of radius 0.15011P to 0.18042P.
(Ext. thd. only) |
B1.15 (Draft) MIL-S-8879A |
| NF |
UNJF |
Unified Inch Screw Thread, fine pitch series, with rounded root of radius 0.15011P to 0.18042P. (Ext. thd. only.) |
B1.15 (Draft) MIL-S-8879A |
| NEF |
UNJEF |
Unified Inch Screw Thread, extra-fine pitch series, with rounded root of radius 0.15011P to 0.18042P. (Ext. thd. only.) |
B1.15 (Draft) MIL-S-8879A |
| N |
UNR |
Unified Inch Screw Thread, constant pitch series, with rounded root of radius not less than 0.108P. (Ext. thd. only.) |
B1.1 |
| NC |
UNRC |
Unified Inch Screw Thread, coarse thread series, with rounded root of radius not less than 0.108P. (Ext. thd. only.) |
B1.1 |
| NF |
UNRF |
Unified Inch Screw Thread, fine pitch series, with rounded root of radius not less than 0.108P (Ext. thd. only.) |
B1.1 |
| NEF |
UNREF |
Unified Inch Screw Thread, extra-fine pitch series, with rounded root of radius not less than 0.108P. (Ext. thd. only.) |
B1.1 |
| UNM |
UNM |
Unified miniature thread series |
B1.10 |
| NS |
UNS |
Unified Inch Screw Thread, special diameter pitch, or length of engagement. |
B1.1 |