High-Quality Metal Washers Service & Factory

While high-speed progressive die stamping is ideal for large-scale, cost-effective flat washers with standard thickness tolerances (typically ±0.05 mm to ±0.1 mm), CNC machining or Swiss-type turning provides sub-micron precision (±0.005 mm), zero rollover edges, and superior perpendicularity and parallelism. Machined washers are required when bearing surfaces must eliminate micro-fretting, when inner bores feature complex chamfers for high-tensile bolt under-head radii (preventing notch-stress failures), or when materials like Titanium Grade 5, Inconel, or custom bronze alloys exceed stamping press tonnages.

For carbon steel washers heat-treated above 320 HV (such as AISI 1070/1095 Belleville discs or 51CrV4 spring washers), acid pickling and electro-galvanizing introduce atomic hydrogen into the steel matrix, which can cause sudden catastrophic failure under load. Sunmy Hardware enforces strict hydrogen de-embrittlement baking per ASTM F1941: parts undergo post-plating baking within 4 hours at 190°C–220°C for 8 to 24 hours depending on the core hardness. Alternatively, we recommend non-electrolytic zinc flake coatings (such as Geomet or Dacromet) that avoid hydrogen pickup altogether.

Yes. For Tier-1 automotive and industrial OEMs, our quality department regularly supplies complete Production Part Approval Process (PPAP) Level 3 packages. This documentation includes Design Records, Process Flow Diagrams, Process FMEA, Control Plans, Measurement System Analysis (MSA) studies, Dimensional Results from in-house CMM, Material/Performance Test Results, Initial Process Capability (Cpk/Ppk ≥ 1.67) studies, and Part Submission Warrants (PSW).

Because Sunmy Hardware operates an agile manufacturing configuration, we support prototype runs through full volume production. For custom CNC-turned washers, our MOQ starts at 50 to 500 units for prototyping, engineering test benches, or high-mix low-volume assemblies. For progressive-die stamped washers requiring dedicated tooling design, we offer rapid single-cavity soft-tooling for initial 1,000-piece pilot runs before scaling into fully automated hard tooling for high-volume runs of 100,000+ pieces annually.

Sealing and valve washers must maintain exact flatness to prevent fluid leaks under high pressure. We utilize a combination of optical flat laser interferometry to measure surface flatness down to helium light bands, combined with high-precision granite surface plates and touch-probe CMM scanning across multiple radial points. Surface roughness is verified using stylus profilometers to guarantee target Ra finishes (down to Ra 0.2 μm) without circular tool marks that could bypass fluid seals.

We work with international enterprise customers via standard wire transfer (T/T), Letters of Credit (L/C at sight), and tailored open account terms (Net 30/60) for qualified long-term OEM contracts. Our shipping department regularly ships under Incoterms 2020 including EXW, FOB Shenzhen/Hong Kong, CIF, and full DDP (Delivered Duty Paid) via air express (DHL/FedEx) or sea/rail freight directly to your assembly line or designated 3PL hub.