Custom Threaded Studs for Machine Tools – Class 10.9

The M8 × 104.25 mm custom threaded studs for machine tools, manufactured by EFS – European Fasteners Solutions according to specific customer requirements, represent one of the most technically demanding applications of special fasteners used in high-stress industrial production lines.

These custom threaded studs for machine tools are produced in quenched and tempered 39NiCrMo3 alloy steel, strength class 10.9, and ensure mechanical strength, dimensional stability, and long-term reliability under dynamic and cyclic loads.

Threaded studs are fasteners with threads at both ends, designed to ensure solid and secure connections between multiple mechanical components.
In some scenarios they may also be referred to as stud bolts, especially when used with nuts on both sides.

Materials and Surface Treatments: 39NiCrMo3 Steel and Electroless Nickel Plating

The 39NiCrMo3 nickel-chromium-molybdenum alloy steel offers an excellent combination of hardness, toughness, and fatigue resistance.
The quenching and tempering treatment provides all mechanical properties required for class 10.9 fasteners, making these custom threaded studs for machine tools suitable for vibration, alternating loads, and severe operating conditions.

The subsequent electroless nickel plating guarantees uniform protection even on complex geometries such as threads, internal corners, and recesses — precisely where traditional electrolytic coatings tend to fail.
Because this coating is deposited through an auto-catalytic chemical reaction, it ensures uniform layer thickness and tight dimensional tolerances.

These are essential for precision assemblies in machine tools.

 

Rolled Threads: Optimized Geometry and Enhanced Fatigue Strength

The threads of these custom threaded studs for machine tools are produced by cold thread rolling.

But, what is the cold thread rolling?

Cold thread rolling is a plastic deformation process in which hardened dies form the thread profile without removing material.
This technique, widely used for high-performance fasteners, creates a denser and stronger surface structure than cut threads.

During thread rolling:

• the metal fibers are aligned and compacted along the thread profile, maintaining material continuity instead of interrupting it through chip removal
• compressive residual stresses develop at the thread root, limiting micro-crack formation and delaying fatigue damage
• the resulting surface is smoother and more uniform, reducing stress concentrations and improving performance under cyclic loads.

Several experimental studies on alloy steel fasteners have confirmed these advantages.
Comparative tests show up to a 100% increase in fatigue resistance over cut threads, thanks to residual compression and improved surface finish (Wang et al., 2022; du Maire, 2015).
Sector analyses (Craig, SPE, 2015) also confirm that rolled threads offer longer service life and more stable tightening under dynamic loads.

The result is a fastening system that remains more stable over time, with higher reliability and reduced fatigue-related failures — essential characteristics in machine tools, gearboxes, and power transmission groups, where precision and operational safety are critical.

 

Typical Applications of Threaded Studs for Machine Tools

These custom threaded studs for machine tools are used in industrial environments where stability, precision, and strength are essential::

• paper mill machinery and continuous production lines, subjected to constant vibration and high temperatures
• machine tool bases and housings, requiring precise and durable component alignment
• gearboxes and transmission units requiring fasteners that guarantee correct centering and rigidity.

 

Production to Drawing and Quality Control

Each stud is supplied by EFS according to customer drawing, with the possibility of defining intermediate lengths, specific heat treatments, customized surface treatments, and centesimal tolerances.
Production includes precision machining, thread rolling, heat treatment, and plating, followed by strict dimensional and visual inspections to ensure full compliance with technical specifications.

Discover all surface treatments and services offered by EFS here.

Thanks to custom manufacturing, these custom threaded studs for machine tools are perfectly compatible with the original mounting seats and guarantee long-term fastening stability, even after years of operation and maintenance.

 

Custom Threaded Studs for Machine Tools: Why Choose EFS

Relying on EFS means choosing a partner able to manage every stage of the supply, from technical drawings to material selection, heat treatments, surface finishing, and laboratory testing.

Our experience with custom threaded studs for machine tools and other high-precision industrial sectors ensures certified, reliable, and fully traceable fasteners fully compliant with international standards.

EFS works exclusively with Italian and European manufacturers and uses European-certified raw materials only.

Every supply comes with complete technical documentation, including EN 10204 3.1 certificates, non-destructive tests, and metallographic analyses.

🔗 See the project images here:
Prigionieri speciali a disegno M8 x 104,25 mm – EFS su LinkedIn

Technical References

Wang, X. et al. “Effects of Deep Rolling on the Microstructure Modification and Fatigue Life of 35Cr2Ni4MoA Bolt Threads”, Metals 12(7), 2022, MDPI.

du Maire, P. “Investigations On The Fatigue Strength Of Threads Produced By Different Fabrication Techniques”, ICSP15 Proceedings, Purdue University.

Craig, B.D., “On the Contradiction of Applying Rolled Threads to Bolting”, Society of Petroleum Engineers (SPE), 2015.