Inch series3 standards16 specification pages
5/16-18 Fasteners
Every 5/16-18 screw, bolt and nut in the database. 5/16-18 has a nominal major diameter of 0.3125 in, threaded 18 tpi to the UNC series, across 3 standards. Rivets are not on this page: they carry no thread, so they are indexed by shank diameter rather than by size designation.
Nominal Ø0.3125 in
Threads per inch18 tpi
Pitch Ø0.2764 in
Tap drill0.2569 in
5/16-18 thread dimensions
Full thread page- Designation
- 5/16-18 UNC
- Major diameter
- 0.3125 in
- Threads per inch
- 18 tpi
- Pitch diameter
- 0.2764 in
- Minor diameter — external
- 0.2445 in
- Minor diameter — internal
- 0.2524 in
- Tap drill size
- Ø 0.2569 in
5/16-18 Bolts
8 pagesASME B18.2.1Hex Head Cap Screw — Inch Series
5/16-18 Screws
7 pagesASME B18.3Socket Head Cap Screw — Inch Series
5/16-18 Nuts
1 pagesASME B18.2.2Hex Nut — Inch Series