DIN 960 Hexagon Head Bolts with Fine Pitch Thread

DIN 960 hexagon head bolts are metric hexagon head fasteners with a partially threaded shank and fine pitch thread. They are commonly referred to as fine thread hex bolts or fine pitch hexagon head bolts. The standard distinguishes this configuration from DIN 931, which uses the corresponding hexagon head bolt geometry with coarse metric thread.

DIN 960 is the traditional DIN designation for hexagon head bolts with metric fine pitch thread, while ISO 8765 is its corresponding international standard designation. Both standards belong to the partially threaded fine pitch hex bolt configuration.

The main difference between DIN 960 and DIN 931 is the thread pitch. For the same nominal diameter, a fine pitch thread has a smaller pitch and more threads per unit length than a coarse pitch thread. This allows finer adjustment of axial position during tightening and can provide greater thread engagement and a larger tensile stress area for a given nominal diameter.

Fine threads can also be useful where a joint requires more precise preload control, where available thread engagement is relatively short, or where the application benefits from the finer adjustment provided by a smaller pitch. The selection between DIN 960 and DIN 931 should therefore be based on the joint design, mating thread and required mechanical characteristics rather than simply the bolt’s nominal diameter.

DIN 960 bolts can be sourced in different material configurations, including carbon steel, stainless steel, alloy steel, copper, titanium and, for application-specific non-metallic versions, nylon and other engineering plastics.

Surface finish options may include plain, black oxide, zinc electroplating, hot dip galvanizing, Dacromet or zinc-flake coatings, and PTFE coatings. Material and coating selection depends on mechanical requirements, corrosion exposure, operating environment and the requirements of the mating components.