ANSI thread series designation
Designations Thread Series B Reference
UN, UNC, UNF UNEF, UNSUnified Inch Screw Threads (UN and UNR Form)B1.1
Gages & Gaging for United Inch Screw ThreadsB1.2
UNJ, UNJC, UNJF, UNJEF, UNJSUnified Inch Screw Threads (UNJ Thread Form)B1.15
Screw Threads Gaging Systems for Dimensional Acceptability-inch and Metric Screw Threads (UN, UNR, UNJ, M and MJ)B1.3
NC-5 HF, NC-5CSFClass 5 Interference-Fit ThreadB1.12
MMetric Screw Threads-M profileB1.13M
Gages and Gaging for Metric M Screw ThreadsB1.16M
MJMetric Screw Threads-MJ ProfileB1.21M
Gages and Gaging for MJ Series Metric Screw ThreadsB1.22M
UNMUnified Minature Screw ThreadsB1.10M
NPTPipe Threads, General PurposeB1.20.1
NPTF, PTF-SAE ShortDryseal Pipe ThreadsB1.20.3
Gaging for Dryseal pipe ThreadsB1.20.5
ANPTPipe Threads, Taper Aeronautical National Form
Symbol ANPT Design and Inspection StandardSAE AS71051
NPSMAmerican Standard Straight Pipe Threads for free-Fitting Mechanical Joints for FixturesB1.20.1
NPSLAmerican Standard Straight Pipe Threads for Loose-Fitting Mechanical Joints with LocknutB1.20.1
NPSCAmerican Standard Straight Pipe Threads in pipe CouplingsB1.20.1
NPSFDryseal American Fuel Internal Straight Pipe ThreadsB1.20.3
NPSIDryseal American Intermediate Internal Straight Pipe ThreadsB1.20.3
NH, NPSH, NHRHose Coupling Screw ThreadsB1.20.7
NHFire Hose ConnectionsNFPA 1963
NGT, SGTNational Gas Taper ThreadsH28/9A
NGONational Gas Outlet ThreadsH28/9A
NGSNational Gas Straight ThreadsH28/9A
R, Rc, Rp (BSPT)British Taper Pipe Threads & Gages (BS-21 obsolete)ISO 7/2
G (BSPP)British Straight Pipe Threads & Gages (BS2779 obsolete)ISO 228-2
BSW, BSFBritish Parallel Screw Threads of Whitworth FormBS84
BABritish Screw ThreadsBS 57
ACMEAcme Screw Threads, General PurposeB1.5
ACME-CAcme Screw Threads, CentralizingB1.5
STUB ACMEStub Acme Screw ThreadsB1.8
BUTTButtress inch Screw threads 7°/45°B1.9
ANSI/AMOMicroscope Objective ThreadsB1.12
AWWAUnderground Service line Valves and FittingsC800-84
DINGerman Specifications
JISJapanese Industrial Standard
ISOInternational Standard Organization