ULAMEX Stainless Steel Nuts are a comprehensive range of A2 stainless steel (1.4301 / AISI 304) nut types specifically selected to pair with every bolt and screw in the ULAMEX PV mounting system. From standard hex nuts for structural joints to sliding channel nuts for tool-free profile positioning — every nut type needed for a complete photovoltaic installation is available from a single source.
Technical Specifications
| Type | Standard | Sizes | Key Feature |
|---|---|---|---|
| Hexagon nut | DIN 934 / ISO 4032 | M8, M10 | General-purpose, pairs with DIN 933 and DIN 912 bolts |
| Flange serrated nut | DIN 6923 / ISO 4161 | M8, M10 | Serrated bearing surface prevents vibration loosening without washer |
| Square nut | DIN 562 | M8 | Low-profile, fits into square recesses in brackets and channels |
| Sliding nut (channel nut) | — | M8 | Slides freely in PV profile T-slot channel for tool-free positioning |
Installation Guidelines
DIN 934 Hexagon Nut: Thread onto the bolt by hand until finger-tight, then tighten with a ring spanner or socket wrench (13 mm for M8, 17 mm for M10). Add a DIN 125 flat washer and DIN 127 spring washer underneath for vibration-prone connections. Torque: M8 = 16–20 Nm, M10 = 30–35 Nm.
DIN 6923 Flange Serrated Nut: The integrated flange with serrated underside replaces the need for a separate washer. The serrations bite into the clamped surface, creating a self-locking connection that resists vibrational loosening. Preferred choice for PV module clamp assemblies where long-term fastener security is critical.
Sliding Nut (Channel Nut / Nutenstein): Insert the sliding nut into the T-slot channel of the PV mounting profile from the open end. The nut slides freely along the channel, allowing tool-free positioning at any point. Once positioned, thread a bolt or component onto it and tighten — the nut rotates and locks against the channel walls. Sliding nuts are the alternative to hammer bolts for applications where components need to be added to an already-assembled rail.
Applications
- Module clamp assemblies — DIN 6923 flange serrated nuts with M8 hammer bolts for vibration-proof module clamping
- Profile connector and cross connector joints — DIN 934 or DIN 6923 M10 nuts with DIN 933 hex bolts
- Roof hook assemblies — M10 hex nuts securing hook-to-rail connections
- Sliding-nut based clamp systems — M8 channel nuts for retrofit and add-on component mounting on existing rails
- Grounding plate connections — M8 nuts securing earthing plates for potential equalisation
- Ballast system assembly — M8/M10 nuts in flat-roof ballast tray connections
Material Properties
All ULAMEX PV nuts are manufactured from A2 stainless steel (1.4301 / AISI 304) — the same grade as the corresponding bolts. This material matching is important: using the same alloy for bolt and nut eliminates galvanic corrosion between the fastener pair and ensures compatible thermal expansion. A2 stainless provides full corrosion resistance in outdoor PV environments without supplementary coatings.
The DIN 6923 flange serrated nut deserves special mention: the serrated underside creates a mechanical lock that exceeds the vibration resistance of standard nut-plus-washer combinations. In wind-loaded PV arrays where dynamic forces continually cycle the fastener, this self-locking feature provides an additional safety margin against loosening.
Compatibility
ULAMEX stainless steel nuts pair with:
- DIN 933 hex bolts (M8, M10) — DIN 934 or DIN 6923 nuts
- DIN 912 Allen bolts (M8) — DIN 934 or DIN 6923 nuts
- Hammer bolts / T-bolts (M8, M10) — DIN 6923 flange serrated nuts (preferred) or DIN 934
- DIN 603 carriage bolts (M10) — DIN 934 hex nuts
- PV profiles 40×40 and 80×40 — sliding nuts in the T-slot channel
- Mid-clamps and end-clamps — via hammer bolt + flange nut assemblies
Why ULAMEX
ULAMEX is an EN 1090 certified B2B wholesaler supplying the full complement of PV fastening hardware. All four nut types are stocked in M8 and M10 sizes for immediate dispatch. One supplier for bolts, nuts, washers, clamps, profiles, and roof hooks — simplifying procurement with one delivery and one invoice. Bulk packaging (100, 250, 500, 1000 pcs) with pallet delivery across Europe.
Frequently Asked Questions
Q: When should I use flange serrated nuts instead of standard hex nuts?
Use DIN 6923 flange serrated nuts for all vibration-exposed connections — which includes virtually every PV mounting joint. The serrated underside provides self-locking security that a standard hex nut cannot match. Standard DIN 934 hex nuts should be supplemented with spring washers (DIN 127) in PV applications.
Q: What is a sliding nut and when do I need one?
A sliding nut (Nutenstein / channel nut) inserts into the T-slot channel of PV profiles and slides freely to any position. Use it when you need to add components to an already-mounted rail (retrofit) or when tool-free positioning is preferred over pre-loaded hammer bolts.
Q: Do I need washers with these nuts?
DIN 6923 flange serrated nuts: No washer needed — the integrated flange serves as washer and locking element. DIN 934 hex nuts: Add a DIN 125 flat washer and DIN 127 spring washer for PV applications to prevent loosening and distribute clamping force.
Q: Are bolt and nut sizes interchangeable between PV systems?
Most PV mounting systems standardise on M8 for clamp assemblies and M10 for structural rail connections. Always verify the bolt size specification in your mounting system documentation before ordering.
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