Solar mounting hardware for rooftop and ground-mount PV
The mounting structure is where PV projects quietly fail: a clamp that is 2 mm out of tolerance cracks a module frame, and a zinc-plated bolt that looked adequate at tender stage shows red rust before year three. This page sets out how to choose the hardware by roof type and by environment.
Choose hardware by roof or foundation type
| System | Fixing method | Typical hardware | Watch out for |
|---|---|---|---|
| Pitched roof, tile | Roof hook into rafter | Solar hanger bolts (wood thread + machine thread), flashings | Rafter spacing and hook height must match the tile profile |
| Standing seam metal roof | Non-penetrating seam clamp | Standing seam anchors, mid and end clamps | Seam geometry is panel-manufacturer specific — never assume |
| Trapezoidal / corrugated metal roof | Self-drilling screw to purlin | Drill fixings with EPDM washer, rails, clamps | Screw length must clear the purlin without bottoming out |
| Flat roof, membrane | Ballasted, non-penetrating | Ballast spikes, interlocking brackets | Wind uplift calculation governs ballast, not the hardware |
| Ground mount, driven piles | Ground screw + tie rod bracing | Ground screw tie rods, HDG bolts, clamps | Bracing pattern and coating thickness for the site's corrosion class |
| Concrete / ballast foundation | Mechanical or chemical anchor | Chemical anchors, wedge anchors, base plates | Edge distance and cracked-concrete approval |
Pick the coating by environment, not by price
| Environment | Recommended protection | Expected service life |
|---|---|---|
| Inland, low humidity | Zinc plated (trivalent passivation) or aluminium 6005-T5 anodised clamps | 10–15 years |
| Industrial / urban | Hot-dip galvanized 65 µm minimum, anodised clamps | 20–25 years |
| Coastal, 1–10 km from sea | Hot-dip galvanized 80 µm+ or A4 (316) stainless | 25 years+ |
| Desert, high dust and heat cycling | Hot-dip galvanized 80 µm minimum, A4 stainless for small fasteners | 25 years+ |
| Chemical / saline exposure | A4 (316) stainless throughout, insulated to avoid galvanic couples | 25 years+ |
Clamp selection: three numbers that decide success
Frame height
Mid and end clamps are dimensioned for a specific module frame height, typically 30–35 mm or 35–40 mm. Clamping outside that range does not grip correctly and can void the module warranty.
Clamping zone
Module manufacturers define a permissible clamping band on the frame. If the rail position falls outside it, the module is not mechanically warranted — check the datasheet before fixing the rail spacing.
Torque
Clamp bolts are tightened to the module maker's stated torque, not to "tight". Over-torque deforms the frame; under-torque lets the module move under wind load.
Hardware used in this application
Solar Mid Clamp
solar mid clamp manufacturer
Solar End Clamp
solar end clamp manufacturer
Solar Hanger Bolt
Solar hanger bolt manufacturer
Solar Ground Screw Tie Rod
solar ground screw tie rod supplier
Solar Complete Clamp Set
solar mounting clamp set supplier
Hot-dip Galvanized Bolt
hot dip galvanized bolt manufacturer
Solar Roof Drill Fixing
solar self drilling screw supplier
Solar Ballast Spike
solar ballast spike supplier
Frequently asked questions
Do you supply complete clamp kits?
Yes. We supply mid and end clamps, bolts and nuts as a configured set with the correct component ratio per module, which removes on-site sorting and short-shipment claims. Ratios can be adjusted to your layout at no extra cost.
Can you match a specific module or roof profile?
Yes. Send the module datasheet (frame height and clamping zone) and the roof panel profile drawing. Clamp geometry and anchor geometry are produced to suit, and we will confirm in writing before tooling starts.
What documentation comes with a PV hardware order?
Coating thickness report for galvanized parts, anodising thickness for aluminium, material certificates for stainless, dimensional inspection report, and a packing list showing the component ratio.
What MOQ applies to custom clamps?
Custom clamp profiles typically start from 2,000–5,000 pieces depending on the extrusion. Standard clamp sizes have flexible MOQ and trial orders are accepted.
Ready to source quality hardware from China?
Tell us the application, the environment and the volumes — we will propose a specification rather than just quoting a part number.