| ACME-C | Acme Thread-Centralizing |
| ACME-G | Acme Thread-General Purpose |
| AMO | American Standard Microscope Objective Thread |
| ANPT | Aeronautical National Form Taper Pipe Thread (Ground thread tap marked NPT) |
| BA | British Association Standard Thread |
| BSF | British Standard Fine Thread Series |
| BSPP | British Standard Pipe (Parallel) Thread |
| BSPT | British Standard Taper Pipe Thread |
| BSW | British Standard Whitworth Coarse Thread Series |
| M | Metric ScrewThread Series |
| N | American National 8, 12 and 16 Thread Series (8N, 12N, 16N) |
| N BUTT | American Buttress Screw Thread |
| NC | American National Coarse Thread Series |
| NEF | American National Extra Fine Thread Series |
| NF | American National Fine Thread Series |
| NGO | National Gas Outlet Thread |
| NGT | National Gas Taper Thread (see “SGT”) |
| NH | American National Hose Coupling and Fire Hose Coupling Threads |
| NPS | For tap marking only (See NPSC, NPSM) |
| NPSC | American National Standard Straight Pipe Thread in Pipe Couplings (Tap marked NPS) |
| NPSF | Dryseal American National Standard Fuel Internal Straight Pipe Thread |
| NPSH | American National Standard Straight Pipe Thread for Hose Couplings |
| NPSI | Dryseal American National Standard Intermediate Internal Straight Pipe Thread |
| NPSL | American National Standard Straight Pipe Thread for Loose Fitting Mechanical Joints with Locknuts |
| NPSM | American National Standard Straight Pipe Threads for Free-Fitting Mechanical Joints for Fixtures (Tap marked NPS) |
| NPT | American National Standard Taper Pipe Thread (See ANPT, NPTR) |
| NPTF | Dryseal American National Standard Taper Pipe Thread |
| NPTR | American National Standard Taper Pipe Thread for Railing Joints (Tap marked NPT) |
| NS | American National Thread-Special |
| PTF | Dryseal SAE Short Taper Pipe Thread |
| SGT | Special Gas Taper Thread |
| SPL-PTF | Dryseal Special Taper Pipe Thread |
| STI | Special Thread for Helical Coil Wire Screw Thread Inserts |
| Stub Acme | Stub Acme Thread |
| *UN | Unified Constant Pitch Thread Series |
| *UNC | Unified Coarse Thread Series |
| *UNEF | Unified Extra Fine Thread Series |
| *UNF | Unified Fine Thread Series |
| UNJ | Unified Thread Series with a 0.15011P to 0.18042P Controlled Root Radius on External Thread only. |
| UNJC | Unified Coarse Thread Series with a 0.15011P to 0.18042P Controlled Root Radius on External Thread only. |
| UNJF | Unified Fine Thread Series with a 0.15011P to 0.18042P Controlled Root Radius on External Thread only. |
| UNM | Unified Miniature Thread Series |
| UNR | Unified Constant Pitch Thread Series with a 0.108P to 0.144P Controlled Root Radius; Ext. thread only. |
| UNRC | Unified Coarse Thread Series with a 0.108P to 0.144P Controlled Root Radius; Ext. thread only. |
| UNRF | Unified Fine Thread Series with a 0.108P to 0.144P Controlled Root Radius; External thread only. |
| *UNS | Unified Thread-Special |
| V | A 60¡ “V” thread with Truncated Crest and Root. The theoretical “V” Form is usually flatted to the user’s specifications. |
| WHIT | British Standard Whitworth Special Thread |
