Server EMI Shielding Cover Sheet Metal Stamping: 0.5mm Galvanized, Finger Springs Formed In-Die
A server EMI shielding cover does two jobs: keep electromagnetic interference inside the chassis, and leave the airflow path open. Base flatness, the contact force of the finger springs around the edges, and surface conductivity all determine whether the machine passes EMC testing - and without an EMC pass, the product never ships.
Project Background & Challenge
A server maker was developing an EMI shielding cover for a 2U platform: 0.5mm galvanized steel, 400×180mm footprint, more than 60 shielding finger springs around the perimeter, stable finger contact force, cover flatness within 0.3mm, at 50,000 pieces a month. Their previous approach - outsourced laser cutting plus manual bending - gave inconsistent fingers and EMC results that varied run to run.
The challenges: fingers are cantilever structures on thin stock where springback is hard to control; 60+ fingers must form in one stroke with even force; and large thin sheets tend to warp in stamping, killing flatness.
BQUQ Process Solution
Fingers Formed In-Die
A dedicated die forms and flattens all finger springs in one press stroke, with bending stations pre-overbent from springback compensation. A fine-adjustment mechanism tunes each station during tryout based on measured data, so no manual straightening is needed in production.
Flatness & Material Control
Galvanized coil is verified for thickness and coating on incoming. A post-stamping leveling pass removes stress-induced warpage; flatness is checked part-by-part on a fixture gauge and finger contact force is force-gauge sampled per batch with records.
Key Specifications
| Item | Specification |
|---|---|
| Material | 0.5mm galvanized steel (stainless/aluminum available) |
| Footprint | 400×180mm class |
| Flatness | ≤0.3mm |
| Finger springs | 60+, formed in one die, force sampled per batch |
| Volume | 50,000 pcs/month |
| Inspection | Flatness gauge 100% + force sampling + salt spray |
| Delivery | Die 20-25 days, first batch 3 weeks |
Quality Control & Delivery
Tryout locks finger force and flatness settings before production; first and last articles are fully checked per batch with in-process finger height sampling; galvanized coating is salt-spray sampled to prevent white rust in transit and storage. First batch of 30,000 ships in 3 weeks, then rolls at 50,000 a month after a first-pass EMC result.
Related Products & Resources
To see more parts in this category and how we scale them, browse the Sheet Metal Enclosures & Covers category page, or these related products:
Related Q&A: How Does Sustainable Stamping Reduce Scrap and Material Waste? More Q&A is in our FAQ Center.
For our capabilities, equipment and quality system, visit About BQUQ and Factory Strength.
FAQ
Can 60+ finger springs hold even contact force?
Yes. All fingers form in one die stroke, so height and angle come from the tool; stations are micro-tuned from tryout measurements and force is sampled per batch with records - far more consistent than manual bending.
How do you keep large thin sheets flat?
Three steps: incoming flatness and stress checks on the coil, a post-stamping leveling pass, and part-by-part fixture verification. Warped batches are caught at leveling, never shipped.
How long does the die take?
20-25 days. Send the drawing and we will review the die structure and finger forming approach, with die and piece-price quotes within 12 hours.
