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We supply full-category shock absorber components, including pistons, stampings, rubber seals, piston rods, springs, and self-developed banding/grooving machines.
High Hardness Welded End Cap
High Hardness Welded End Cap by XIAYI starts with spectrum-verified DC04 deep drawing steel and ends at 48 MPa bearing pressure with 1,200,000 hydraulic impacts behind it. Sourced from China with full batch test reports, it gives your shock line strength you can audit, not just a hardness claim.
A hard cap made from soft steel is marketing, not engineering. The High Hardness Welded End Cap is built on a material selection system that matches base steel to real load duty: SPHC hot-rolled stamping steel for passenger cars, DC04 deep-drawing cold-rolled steel for SUV and heavy-use applications, and 304 stainless steel for coastal high-salt environments. Each sheet is spectrum-verified on arrival — carbon, manganese and silicon content checked per coil, ultrasonic inspected for delamination and inclusions — because internal defects in cheap substitute sheet turn into side-wall tearing at the press and cracking on the vehicle.
Three Base Materials, Three Duty Levels
| Material | Key Performance | Intended Use |
|---|---|---|
| SPHC hot-rolled steel | Tensile ≥ 330 MPa, elongation ≥ 35%, 300 h salt spray, crack-free stamping | Family passenger car shocks |
| DC04 deep-drawing steel | Tensile 300–360 MPa, elongation ≥ 40%, 500 h salt spray, extreme deep drawing without cracks | Modified / city SUV shocks — main grade of this product |
| 304 stainless steel | Tensile ≥ 500 MPa, 800 h salt spray without red rust, galvanic-corrosion resistant | Coastal high salt-fog regions |
Watch out for substitutes: low-grade recycled mixed steel (elongation < 32%) tears during deep drawing, ordinary DC01 shallow-drawing steel leaves invisible micro cracks inside the cavity, and low-nickel 201 stainless turns brittle with only ~200 h of salt spray resistance.
Mechanical Acceptance — Numbers You Can Audit
| Acceptance Item | Standard |
|---|---|
| Ultimate bearing pressure | ≥ 48 MPa (DC04 grade), ≥ 34 MPa (SPHC grade), ≥ 45 MPa (304 stainless) |
| Hydraulic impact endurance | Zero indentation, crack or deformation after 1,200,000 reciprocating impacts |
| Thermal stability | No warpage after −40 ℃ to +130 ℃ hot-cold cycling (stress relieved by 450 ℃ vacuum annealing) |
| Coating adhesion | No large-area peeling after repeated 3M tape tearing test |
≥ 48 MPa
Ultimate bearing pressure (DC04)
1.2 M
Hydraulic impact cycles, zero defects
800 h
Salt spray (304 grade), no red rust
Structural Details That Carry the Load
- 1.8× thickened curled sealing groove — one-piece curling thickened to 1.8 times base material, giving the weld a solid landing zone instead of a thin edge that cracks under pressure
- Built-in central buffer boss — boss height tolerance ±0.02 mm, stabilizing the damping buffer stroke
- Mirror-polished inner cavity — Ra ≤ 0.3 μm, no stamping burrs to scratch the bottom piston oil seal
- 450 ℃ vacuum stress-relief annealing — residual stamping stress removed so the cap stays flat through years of hot-cold alternation
- Micron-level dimensional map — cavity OD ±0.04 mm, cavity depth ±0.03 mm, wall uniformity ±0.03 mm, overall flatness ≤ 0.02 mm
FAQ
Q: Which material grade should we specify?
A: DC04 is the default for SUV and heavy-use programs because its elongation ≥ 40% eliminates the hidden micro cracks that DC01 leaves after deep drawing. For coastal fleets we recommend the 304 grade; for standard passenger cars, SPHC keeps cost down without giving up verified strength.
Q: Can you customize cavity dimensions to our cylinder?
A: Yes — cavity outer diameter, cavity depth, wall thickness, buffer boss height and curling groove dimensions are adjusted 1:1 to your shock cylinder drawing, with full-dimension reports supplied per batch.
Q: What documentation comes with each shipment?
A: Sheet spectrum reports, stamping PFMEA records, hydraulic impact/leakage test reports and salt spray reports are delivered with every batch — ready for your quality audit and platform compliance checks.
Send your cylinder drawing — get a material-matched quotation
Ningbo XiaYi Electromechanical Tech Co., Ltd. offers 12 years of custom end cap manufacturing with spectrum-certified materials. Tell us your inner diameter, oil pressure and climate zone for a grade recommendation and sample.
About XIAYI material discipline: XIAYI treats incoming steel as the first quality gate — every coil is spectrum-tested and ultrasonic-inspected before it is allowed near a press, and any sheet with excessive inclusions or insufficient elongation is scrapped on arrival rather than "reworked" into your supply chain.
Hot Tags: High Hardness Welded End Cap, China, Manufacturer, Supplier, Factory
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Contact Info
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Address
No.209 Lane 520 Tongning Rd,Qianjiang Street,Jiangbei District, Ningbo City, Zhejiang Province, China
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Get a Tailored Quote for Your Shock Absorber Parts
Why Global Buyers Choose Ningbo Xiayi:
✓ IATF 16949 Certified — Defect rate strictly controlled below 0.1%.
✓ Full-Category Supply — Pistons, rods, springs, stampings & rubber parts.
✓ R&D Support — Custom powder metallurgy formulas & 7-10 day rapid prototyping.
✓ Proven Capacity — 50 million core pistons produced annually for global OEMs.
Ready to start? Complete the form below and our engineering team will respond within 24 hours with a custom recommendation.
