Brass Cup Washers | Copper Cup Washers | Dome Washers | Countersunk Cup Washers Manufacturer India
Manufacturer–Exporter of Brass and Copper Cup washers from India |
Overview
We are a leading manufacturer and exporter of Brass Cup Washers, Copper Cup Washers, Dome Washers, Countersunk Cup Washers, and Finishing Cup Washers from India. Also called screw cup washers, raised cup washers, or domed cover washers, these pressed metal components provide a neat, decorative, and protective finish to screw and bolt heads — preventing surface damage, distributing load, and concealing fastener heads in wood, composite, and panel applications. We supply brass and copper cup washers to furniture manufacturers, marine equipment builders, construction hardware suppliers, and general engineering OEMs across the USA, UK, Europe, Australia, and the Middle East.
What Are Cup Washers?
A cup washer (also known as a dome washer, screw cup, finishing washer, countersunk washer, or raised washer) is a pressed metal formed washer with a raised cup or dome shape designed to seat the head of a countersunk (CSK) or raised-head screw, protecting the substrate surface and providing a clean finished appearance. Brass and copper cup washers are specifically valued for their decorative gold and copper colour, corrosion resistance, and compatibility with brass wood screws in period furniture, joinery, marine installations, and architectural hardware. Related terms include: brass screw cups, copper screw cups, dome washers, countersunk finishing washers, brass raised washers, decorative cup washers, CSK cup washers, copper dome washers, brass escutcheon washers, and brass cover washers.
Material Grades & International Equivalents
Brass Grades for Cup Washers:
ASTM / CDA: C26000 (Cartridge Brass 70/30) – bright, excellent formability | C27000 (Yellow Brass 65/35) – high volume presswork | C28000 (Muntz Metal 60/40) – cost-effective general purpose | C36000 (Free Cutting Brass) – machined / multi-operation parts
DIN / EN: CW508L (CuZn37) | CW505L (CuZn30) | CW612N (CuZn39Pb3) per EN 1172, EN 12449
BS: CZ108 (70/30 Brass) | CZ107 (65/35 Brass) | CZ109 (60/40 Brass)
IS: IS 319 Grade 1 and Grade 2 | JIS: C2600, C2700, C2800
Copper Grades for Cup Washers:
ASTM: C11000 (ETP Copper) – pure copper, maximum conductivity and natural copper colour | C12200 (DHP) – deoxidised, excellent forming | C10200 (OF) – oxygen-free, premium grade
DIN / EN: CW004A (Cu-ETP) | CW024A (Cu-DHP) per EN 13601
BS: C101, C103, C106 | IS: IS 191 ETP / FRHC / OFC
Types of Cup Washers We Manufacture
Our comprehensive cup washer range includes: Brass Countersunk (CSK) Cup Washers for No. 4 to No. 14 wood screws and M3 to M12 machine screws, Copper Countersunk Cup Washers matching standard screw sizes, Raised / Dome Head Cup Washers (hemispherical dome for decorative applications), Flat-Seat Cup Washers (for pan-head and raised countersunk screws), Large Flange Cup Washers (extended OD for soft substrates), Brass Escutcheon Plates and Cover Washers (architectural/decorative), Marine-Grade Brass Cup Washers (dezincification-resistant DZR brass available), Nickel-Plated and Chrome-Plated Brass Cup Washers, and Custom Profile Cup Washers to drawing or sample.
Design & Manufacturing Capabilities
Cup washer sizes are produced to match standard countersunk screw head angles (60°, 82°, 90°, 100°) and screw shank diameters. Standard screw compatibility: No. 2 through No. 14 (imperial) and M2 through M16 (metric). Custom sizes to drawing. Flange OD: 8 mm to 50 mm. Material thickness: 0.4 mm to 2.0 mm. Press operations: single-hit compound dies and progressive dies for high-volume production. Tolerances: ±0.05 mm on all critical dimensions. Surface finishes: natural brass, natural copper, bright polished, satin, nickel-plated, chrome-plated, antique brass, gold PVD, silver-plated. Secondary operations: polishing, vibratory tumbling, barrel plating, lacquering, and laser marking. MOQ 500 pcs for standard sizes; 5,000 pcs for custom sizes.
Technical Specifications
| Parameter | Brass Cup Washer | Copper Cup Washer |
|---|---|---|
| Material | C26000 / C27000 / C28000 Brass | C11000 / C12200 Copper |
| Hardness | HV 90–150 (H02–H04 temper) | HV 55–90 (H01–H02 temper) |
| Tensile Strength | 340–500 MPa | 200–350 MPa |
| Screw Head Angle | 60°, 82°, 90° or 100° (to order) | 60°, 82°, 90° or 100° (to order) |
| Standard Size Range | No. 4 – No. 14 / M3 – M12 | No. 4 – No. 14 / M3 – M10 |
| Tolerance (OD/ID) | ±0.05 mm | ±0.05 mm |
| Corrosion Resistance | Very Good (excellent with Ni/Cr plate) | Excellent (natural patina) |
| Finish Options | Natural, polished, Ni, Cr, antique, PVD | Natural, polished, tinned, Ni, Ag |
Applications & Industries
Furniture & Joinery (brass wood screw cups for cabinet doors, drawer hardware, period furniture), Marine & Boat Building (brass and copper cup washers for teak decks, instrument panels, interior fittings), Architectural Hardware (decorative brass escutcheon washers, door and window fittings), Construction (cladding and panel fastening, roofing and timber frame assembly), Musical Instruments (brass cup washers for guitar hardware, piano mechanisms), Electrical Enclosures (copper cup washers for grounding screws in panels and switchboards), and DIY / Retail (pre-packed assorted brass screw cup sets for home improvement).
ISO Certification & Quality Assurance
CGI is ISO 9001:2015 certified. Cup washer quality controls include: incoming material verification by XRF spectro analysis for brass and copper grades, dimensional inspection (OD, ID, depth, flange angle) by optical comparator and gauges, surface finish inspection under uniform lighting, 100% visual inspection for burrs, cracks, and plating defects, and AQL 1.5 sampling for critical dimensional checks. Packing: clear poly bags with part labels, retail blister packs available, bulk carton or box packing for trade customers. Certificates: EN 10204 3.1 MTC, CoC, RoHS, REACH SVHC Declaration.
Frequently Asked Questions
Q1. What is the purpose of a cup washer compared to a standard flat washer?
A standard flat washer spreads load under a bolt or screw head. A cup washer (screw cup) additionally seats and conceals the screw head, provides a decorative raised dome appearance, protects the surface material from the screw head cutting in, and creates a professional finished look — particularly important in furniture, marine joinery, and architectural hardware.
Q2. What size brass cup washers are available for standard wood screws?
We stock and manufacture brass cup washers for No. 4, No. 6, No. 8, No. 10, No. 12, and No. 14 wood screws (imperial), and M3, M4, M5, M6, M8, M10, and M12 countersunk machine screws (metric). Custom sizes are available to drawing.
Q3. Why use copper cup washers instead of brass?
Copper cup washers are used where pure copper’s natural antimicrobial surface is beneficial (food and medical environments), where a distinctive warm copper-red appearance is desired for decorative purposes, or where electrical conductivity and grounding continuity across the fastener joint is required.
Q4. Are your brass cup washers dezincification resistant for marine use?
Yes. For marine and saltwater applications, we can supply cup washers in DZR (Dezincification Resistant) brass per ISO 6509, typically using CW602N (CuZn36Pb2As) or CW724R (CuZn21Si3P) alloys that resist selective zinc leaching in seawater.
Q5. Do you supply nickel-plated or chrome-plated brass cup washers?
Yes. We supply brass cup washers in bright nickel plated (5–10 µm), bright chrome plated (3–5 µm chrome over copper-nickel undercoat), antique brass plated, satin nickel, and gold PVD finishes for decorative architectural and furniture applications.
Q6. Can CGI s supply retail-packaged brass cup washers for trade merchants?
Yes. We offer blister-pack and poly-bag retail packaging with barcode labels and product description cards for trade and DIY customers. Custom branded packaging is available for larger volume orders.
Why Choose us for Brass and Copper Cup Washers?
Three decades of decorative and functional press work in brass and copper | Wide range of standard sizes in stock; custom sizes from drawing in 3–4 weeks | Full plating and surface treatment capability | Export to 40+ countries including UK, USA, Australia, UAE, and Europe | Competitive pricing from USD 10–20/kg CIF | ISO 9001:2015 certified, RoHS and REACH compliant | Retail packaging and private label options available.
Request a Quote – Brass Cup Washers and Copper Cup Washers
Tell us your screw size (imperial or metric), preferred material (brass or copper), required finish, quantity, and any specific standards — we will respond within 24 hours with pricing and lead time. Email: sales@cableglandsindia.com | Phone: +91 22 4344 9300. Request samples, download our product catalogue, or enquire about retail packaging options today.