L-foot solar roof hook

Specifications

Product Specification Sheet
Product Name	L-Foot Solar Roof Hook with Anti-Slip Serrations for PV Mounting Rails
Part No.	SRH-L01
Category	Solar mounting brackets
Overview	SRH-L01 is an L-shaped welded roof hook: a flat base plate with three mounting holes is fixed onto the rafter, and a vertical post fillet-welded to it carries transverse anti-slip serrations plus one vertical slotted hole for height adjustment of the aluminium PV rail.
Version	V1.0 \| 2026-09-15
Material
Main material	SUS304 stainless steel — flat base plate plus vertical post, joined by fillet welding
Grade and standard	SUS304 / AISI 304 / EN 1.4301 plate per ASTM A240 or GB/T 3280; welding consumable ER308L （TIG） or A102 electrode
Alternative material	SUS316L （EN 1.4404） for coastal C5 sites; Q235B / Q355B carbon steel with hot-dip galvanizing for inland cost-sensitive projects
Raw material form and thickness	Base plate 5 mm （0.197 in） cold-rolled plate; vertical post 5 mm （0.197 in） flat bar, width 40 mm （1.575 in）
Mechanical properties	Plate ≥ 515 MPa tensile / ≥ 205 MPa yield; weld metal tensile strength ≥ 550 MPa, elongation ≥ 35 %
Material certificate	MTC with heat number and chemical/mechanical data per lot for plate, flat bar and welding consumables; PMI re-check on request
Service environment and design life	Outdoor rooftop exposure （C4/C5）, 25-year design service life with matched SUS304 fasteners and periodic serration/weld inspection
Process
Cutting	CNC laser cutting of the flat base plate and the post blank; base plate corners rounded R5 mm
Forming （bending）	No bending on the base plate （flat）; post blank straightened and flattened, no press-brake bends in this model
Joining （welding）	Vertical post fillet-welded to the base plate on both sides along the joint, fillet leg size 4–5 mm （0.157–0.197 in）, continuous weld, TIG or MIG
Secondary machining	Base plate 3 round holes Ø9 mm （0.354 in）; 1 vertical slotted hole 11 × 25 mm （0.433 × 0.984 in） in the upper post; transverse anti-slip serrations cut into the post face
Serrations forming	Transverse anti-slip serrations on the upper half of the post, pitch 2.0 mm （0.079 in）, tooth depth 0.8 mm （0.031 in）, formed by CNC milling or press-forming with a serrated die
Surface pre-treatment	Weld spatter and heat tint removal by shot blasting; serrated zone protected from over-polishing to keep tooth profile sharp
Key process control points	Post perpendicularity to base plate （welding jig）, serration pitch/depth consistency, slot straightness, and weld leg size at the post-to-base joint
Process route	Incoming inspection → laser cutting → deburring → serration milling → welding （jig） → shot blasting → pickling and passivation → dimensional and tooth inspection → packing
Surface treatment
Treatment method	Shot blasting + pickling and passivation on the whole part including the serrated post face; no painting or plating for the stainless version
Coating or layer thickness	Passive film only （not measurable）; carbon-steel alternative: hot-dip galvanizing 65–85 µm （2.6–3.3 mil）, serration roots ≥ 55 µm
Color and appearance	Uniform matte silver-grey / brushed stainless appearance; no heat tint, spatter, burr or sharp edge on the serrations
Standard and salt spray	Passivation per ASTM A967 / GB/T 25150; neutral salt spray （ASTM B117） ≥ 480 h without red rust including the welded joint and serrated zone
Surface roughness	Ra 1.6–3.2 µm on blasted faces; serration flanks kept in the as-machined range to retain friction
Pre-treatment	Alkaline degreasing → rinse → weld slag/heat tint removal → acid pickling → passivation → DI rinse → drying
Tolerance
Overall profile tolerance	General tolerance ISO 2768-m / GB/T 1804-m; base plate length ±1.0 mm （0.039 in）, post height ±1.0 mm （0.039 in）
Hole diameter and position	Round holes Ø9 mm （0.354 in）, +0.2/0 mm, 3 pcs; vertical slot 11 × 25 mm （0.433 × 0.984 in）, +0.3/0 mm; hole position ±0.5 mm （0.020 in）
Bend angle and radius	Not applicable — no press-brake bends in this L-foot model; base plate remains flat with flatness ≤ 0.5 mm per 100 mm （0.020 in / 3.937 in）
Weld position tolerance	Post centred on the base plate within ±1.0 mm （0.039 in）; post perpendicularity to base ≤ 0.5 mm per 100 mm; fillet leg 4–5 mm, throat ≥ 3.5 mm, undercut ≤ 0.2 mm
Serration tolerance	Serration pitch 2.0 mm ±0.1 mm （0.079 ± 0.004 in）; tooth depth 0.8 mm ±0.1 mm （0.031 ± 0.004 in）; serrated band length ±1.0 mm
Flatness and straightness	Base plate flatness ≤ 0.5 mm per 100 mm after welding; post straightness ≤ 0.5 mm over its full height
Assembly and adjustment fit	Vertical slot allows ≥ 15 mm （0.591 in） height adjustment of the rail; serration engagement clearance ≤ 0.3 mm （0.012 in）
Dimensional basis	Dimensioning and acceptance follow the customer drawing and technical agreement; values above are industry recommended values for reference
Packaging
Surface protection	Each piece wrapped in kraft paper or PE film with serrated faces facing each other separated by cardboard; avoid metal-to-metal rubbing
Inner packaging	30 pcs per inner carton with dividers
Outer packaging	Export 5-ply corrugated carton on fumigation-free plywood pallet, PP strapping, corner protectors and moisture-proof liner
Quantity, carton size and gross weight	120 pcs per carton; carton 400 × 300 × 250 mm （15.75 × 11.81 × 9.84 in）; gross weight approx. 27 kg （59.5 lb）
Marking and shipping marks	Part no. SRH-L01, product name, quantity, lot no., welder/date code, production date, customer shipping mark and MADE IN CHINA
Container loading and stacking	Pallets stackable 5 layers; 1 × 20' GP holds approx. 22 pallets （about 2,600 pcs）
Storage and transport	Indoor dry storage away from chloride and carbon steel; do not drag serrated parts on hard floors; keep original packaging until installation
Quality control
Incoming inspection	MTC review and PMI for SUS304 plate/flat bar; thickness 5 mm ±0.2 mm; straightness and surface check; welding consumable batch verification
First article approval	FAI covering dimensions, post perpendicularity, serration pitch/depth, weld leg size and weld macro section before batch release
In-process inspection frequency	Serrations checked every 2 hours （pitch/depth gauges）; weld visual 100 %; perpendicularity sampled every 100 pcs
Final and outgoing inspection	Sampling per GB/T 2828.1 / ISO 2859-1, AQL 1.0 （major） / 2.5 （minor）; 100 % visual plus sampled dimensional, serration and weld checks
Inspection equipment	Weld gauge （fillet leg/throat）, serration pitch gauge and depth gauge, digital caliper/micrometer, height gauge, square and dial indicator, CMM, roughness tester, salt spray chamber
Records and reports	Dimensional report, serration inspection record, weld inspection record, MTC and salt spray report per lot, traceable by lot number
Nonconforming product handling	NCR issued; blunt or wrongly pitched serrations are re-machined once and re-inspected; cracked or over-ground parts are scrapped; no re-welding of galvanized parts without re-galvanizing
Quality system and certificates	Manufactured in an ISO 9001:2015 certified plant in Shandong, China; welding performed per qualified WPS with welder qualification records; no third-party certificate number claimed unless issued for the specific order

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