Toprecision — Precision Fastening & Connection Solutions

Two screws from identical steel can differ 30% in fatigue life. The difference is not chemistry — it is grain flow.

Bottom line: for most Precision Screws applications the decision comes down to load, environment and assembly method — the Precision Screws guide walks through the selection.

What cold heading does to the metal

Cold heading deforms wire at room temperature between dies. The crystal grains elongate and flow around the head contour continuously — like wood grain around a knot. Cut threads then roll the shank, densifying surface layers. The result: continuous grain lines following the part geometry, work-hardened surfaces, and fatigue strength a machined-from-bar equivalent cannot match.

Where machining remains right

• Low volumes, prototypes, and diameters beyond heading machine capability.
• Complex heads (custom hexalobes, flange-under-cut geometries) where die cost is unjustified.
• Ultra-precise micro parts where machining centers hold tighter tolerances.

The economic crossover

Above roughly ten thousand pieces, heading die amortization beats per-part machining cost — usually by a factor of five on simple geometries. Topprecision runs both processes and quotes honestly: we recommend heading where volume justifies it and machining where flexibility does, and our cold-headed 7-series aluminum bolt line exists precisely because grain flow makes aluminum bolts structurally viable.

Key specifications at a glance

Need cold-formed fastener manufacturing?

Toprecision cold-heads M1.6–M24 fasteners in-house, with thread rolling, heat treatment and all surface treatments under one roof. Send the drawing and annual volume — we will recommend the process and supply sample pieces. Request manufacturing support.