Product overviewJam nuts are thin hex locking nuts installed against a standard nut to lock the assembly in place. They provide additional axial resistance to help prevent loosening under vibration or dynamic loads and are commonly used in industrial and mechanical assemblies.
Key features- Available in coarse (UNC) and fine (UNF/UNS) threads
- Materials: zinc-plated mild steel and 18-8 stainless steel options
- Hex form factor with multiple sizes covering small to large diameters (1/4-28 to 1-1/2-12)
- Used as a locking element with a standard nut for secure fastening in assemblies
Available parts and part numbersMild Steel, Fine Thread- 1/4-28 UNF — 14639
- 3/8-24 UNF — 14651
- 1/2-20 UNF — 14664
- 3/4-16 UNF — 14687
- 1-12 UNF — 14702
- 1-14 UNF — 14703
- 1 1/4-12 UNF — 14708
- 1 1/2-12 UNF — 14711
Mild Steel, Coarse Thread- 1/4-20 UNC — 14636
- 3/8-16 UNC — 14649
- 1/2-13 UNC — 14661
- 5/8-11 UNC — 14676
- 3/4-10 UNC — 14686
- 1-8 UNC — 14701
- 1-1/4-7 UNC — 14707
Stainless Steel, Fine Thread- 1/4-28 UNF — 14640
- 1/2-20 UNF — 14665
- 3/4-16 UNF — 14688
Stainless Steel, Coarse Thread- 3/8-16 UNC — 14653
- 1/2-13 UNC — 14662
- 5/8-11 UNC — 14680
- 3/4-10 UNC — 14690
Technical specifications- Function: Thin jam nuts used in combination with standard nuts to lock and prevent loosening by providing extra axial resistance.
- Thread types: Coarse (UNC) and fine (UNF/UNS) thread series.
- Materials: Zinc-plated mild steel (clear zinc) and 18-8 stainless steel (SST) options.
- Form factor: Hex jam nuts; width across flats (WAF) and thickness vary by part number.
- Available parts and typical Width Across Flats (WAF) / Thickness by part number: 14639 — 1/4-28 UNF, WAF 7/16, Thickness 5/32; 14651 — 3/8-24 UNF, WAF 9/16, Thickness 7/32; 14664 — 1/2-20 UNF, WAF 3/4, Thickness 5/16; 14687 — 3/4-16 UNF, WAF 1-1/8, Thickness 27/64; 14702 — 1-12 UNF, WAF 1-1/2, Thickness 35/64 (clear zinc plated); 14703 — 1-14 UNS, WAF 1-1/2, Thickness 35/64; 14708 — 1-1/4-12 UNF, WAF 1-7/8, Thickness 23/32; 14711 — 1-1/2-12 UNF, WAF 2-1/4, Thickness 27/32; 14636 — 1/4-20 UNC, WAF 7/16, Thickness 5/32; 14649 — 3/8-16 UNC, WAF 9/16, Thickness 7/32; 14661 — 1/2-13 UNC, WAF 3/4, Thickness 5/16 (Steel Grade A, zinc plated); 14676 — 5/8-11 UNC, WAF 15/16, Thickness 3/8 (clear zinc plated); 14686 — 3/4-10 UNC, WAF 1-1/8, Thickness 27/64; 14701 — 1-8 UNC, WAF 1-1/2, Thickness 35/64; 14707 — 1-1/4-7 UNC, WAF 1-7/8, Thickness 23/32; 14640 — 1/4-28 UNF SST, WAF 7/16, Thickness 5/32; 14665 — 1/2-20 UNF 18-8 SST, WAF 3/4, Thickness 5/16; 14688 — 3/4-16 UNF SST, WAF 1-1/8, Thickness 27/64; 14653 — 3/8-16 UNC SST, WAF 9/16, Thickness 7/32; 14662 — 1/2-13 UNC 18-8 SST, WAF 3/4, Thickness 5/16; 14680 — 5/8-11 UNC 18-8 SST, WAF 15/16, Thickness 3/8; 14690 — 3/4-10 UNC SST, WAF 1-1/8, Thickness 27/64.