C-channel cantilever bracket

Specifications

Product Specification Sheet
Product Name	Roll-formed C-Channel Cantilever Arm Bracket for Solar Module Mounting
Part No.	SCB-01
Category	Solar mounting brackets
Overview	Cantilever bracket for PV mounting frames, combining a roll-formed cold-bent C-channel （strut with inward lips） welded at one end to a heavy rectangular base plate. Vertically arranged slots on the base plate and an evenly pitched slot row on the channel back give adjustable, high-leverage support for modules and cable trays.
Version	V1.0 \| 2026-09-15
Material
Main material	Q235B carbon steel （base plate） + cold-rolled C-channel strut, both hot-dip galvanized
Grade and standard	Q235B per GB/T 700-2006; C-channel per GB/T 6723 cold-formed steel section （S235JR equivalent per EN 10025-2）
Alternative material	SUS 304 stainless steel; Q355B / S355JR high-strength C-channel for long cantilever spans
Raw material form and thickness	Base plate 8.0 mm （0.315 in） flat plate + C-channel 2.5 mm （0.098 in） cold-rolled coil （approx. 12 gauge）
Material certificate	EN 10204 3.1 mill certificate per heat / coil number for both plate and coil
Process
Cutting / blanking	Base plate CNC plasma / laser cut with slots punched or cut in the same setup; C-channel cut to length by cold saw or shear
Forming	C-channel produced by roll forming （cold bending）: 90° outer bends plus inward-curled lips at the opening; base plate remains flat
Joining	Continuous fillet welding （MIG） around the C-channel-to-base-plate joint: both side walls and bottom, weld leg 4-5 mm
Secondary operations	3 vertical slots 14 x 30 mm （0.551 x 1.181 in） on base plate; evenly pitched slot row approx. 11 x 30 mm （0.433 x 1.181 in） on channel back; deburring and edge rounding
Surface pretreatment	Weld spatter and slag removal, weld toe dressing, alkaline degreasing, acid pickling, fluxing
Key process control points	Cantilever perpendicularity of channel to base plate （90° +/- 1°）, weld leg size and continuous fillet, distortion control, slot pitch accuracy
Surface treatment
Treatment method	Hot-dip galvanizing after welding and roll forming; full assembly dipped as one unit; green plastic end cap fitted after galvanizing
Coating thickness	Average zinc layer >= 70 µm （0.0028 in）, local minimum >= 55 µm （0.0022 in）
Color and appearance	Matte silver-grey galvanized surface with normal zinc spangle; green plastic cap at channel end; no uncoated area or flaking
Standard and salt-spray requirement	HDG per GB/T 13912-2020 （ISO 1461 equivalent）; NSS per GB/T 10125 / ISO 9227 >= 480 h without red rust
Surface roughness	Ra <= 12.5 µm on galvanized surfaces; C-channel inner surface free of zinc lumps to allow nut insertion
Pretreatment	Degreasing - pickling - rinsing - fluxing; internal cavity and lip gap cleaned before dipping
Tolerance
Overall profile tolerance	Base plate length / width +/- 1.0 mm （+/- 0.039 in）; cantilever length +/- 1.5 mm
Hole diameter and position tolerance	Base slots 14 x 30 mm +0.5/0 mm at 60 mm pitch +/- 0.5 mm; channel back slots 11 x 30 mm at 50 mm pitch +/- 0.5 mm
Bend angle and bend radius tolerance	C-channel outer bends 90° +/- 1.5°; inner bend radius 2.5 mm （0.098 in） approx. 1.0 x t; lip curl radius 3 mm （0.118 in） +/- 0.5 mm
Weld position tolerance	Channel-to-plate perpendicularity 90° +/- 1° （0.5 mm over 100 mm）; weld position +/- 2.0 mm per GB/T 19804
Flatness and straightness	Base plate flatness <= 1.5 mm / 100 mm; C-channel straightness <= 1.5 mm over full cantilever length
Assembly fit tolerance	Channel opening and lip gap sized for standard strut nuts （M10 / M12, 3/8 in / 1/2 in） with free sliding fit; base slots for M10-M12 anchor bolts
Dimension basis	Customer drawing / 3D model prevails; unspecified tolerances per GB/T 1804-m, GB/T 6723 and GB/T 19804
Packaging
Surface protection	VCI anti-rust paper + PE film on base plate face; plastic cap kept fitted during transport
Unit inner packaging	10 pcs bundled with PP strap, kraft paper interlayer between bundles
Outer packaging	Wooden pallet with carton / crate, stretch film wrapped, steel or plastic edge protectors
Quantity, carton size and gross weight	80 pcs per pallet; pallet 1200 x 1000 x 900 mm （47.2 x 39.4 x 35.4 in）; gross weight approx. 300 kg
Marking and shipping marks	Part no. SCB-01, batch no., heat / coil no., quantity, net/gross weight, carton no.; marks per customer requirement
Container loading and stacking	Max stacking 3 pallets high; 20GP approx. 16 pallets / 40HQ approx. 36 pallets
Storage and transport	Dry ventilated warehouse, palletized off the ground, protected from rain and standing water
Quality control
Incoming inspection	Mill certificate check for plate and coil, thickness and section dimension measurement of C-channel, welding wire certificate check
First article approval	First article with full dimensions, perpendicularity, slot pitch, strut-nut sliding fit test and weld macro check
In-process inspection frequency	Roll-forming / welding line checked every 2 hours; dimensional patrol every 200 pcs; slot pitch gauge check each shift
Final and pre-shipment inspection	100% visual on welds, coating and cap fitting; AQL 1.0 for critical dimensions; coating thickness per pallet; salt-spray sampling per batch
Inspection equipment	CMM, digital caliper, height gauge, weld gauge, square / protractor, section template, coating thickness gauge, salt-spray chamber
Records and reports	Roll-forming parameter record, WPS/weld record, dimensional and coating reports, mill certificate and COC per shipment; kept 3 years
Nonconforming product handling	Segregated and red-tagged; weld defects repaired per approved WPS and re-inspected; blocked strut cavity （zinc lumps） reworked or rejected; over-bent channel scrapped
Quality system and certification	ISO 9001:2015 certified factory; WPS / PQR and welder qualification on file; PPAP / 8D support on request
Notes	The parameters listed in the table are standard values based on product photographs and our factory's standard manufacturing processes. For items marked as "Recommended Values," as well as all dimensions, materials, and tolerances, the final specifications shall be determined by the customer's drawings (2D/3D), technical agreements, and the results of the first-article inspection.
Drawing Format	3D: .step / .stp / .igs 2D: .dxf / .dwg / .pdf
For Quotation	Drawing + material + surface treatment + quantity + tolerance requirement