What Are Brass Cup Washers?
Brass cup washers (also known as brass finishing washers, countersunk washers, or dress washers) are decorative and functional washers with a countersunk or cup-shaped profile that neatly seats around a flat-head or oval-head screw, providing a finished aesthetic appearance while distributing the clamping load across a wider surface area. Jamnagar Brass Components manufactures premium-quality brass cup washers in a full range of screw sizes and countersink angles for the US woodworking, furniture, marine, and architectural markets.
Types of Brass Cup Washers We Manufacture
Countersunk (Flat Head) Brass Cup Washers
The standard profile — a conical recess matching 82° or 90° countersunk screw heads. Available for #4 through #14 screw sizes (US) and M3 through M10 (metric). Widely used in hardwood flooring, cabinetry, and marine decking installations across the USA.
Oval Head Brass Cup Washers
Designed to partner oval-head (raised countersunk) screws, these washers provide a more pronounced domed appearance favored in furniture and architectural joinery. Popular with US furniture manufacturers and cabinet makers.
Large Diameter Brass Cup Washers (Repair Washers)
Oversized OD cup washers used when enlarging a fastener hole or providing extra load distribution in soft woods, composites, or fiberboard. Available with inside diameters from #6 to 1/2″ with OD up to 1-1/2″.
Stepped / Shouldered Brass Cup Washers
Feature a raised shoulder below the cup that locates the washer precisely in a drilled counterbore. Used in precision assemblies where washer positioning must be consistent, such as musical instruments and precision cabinetry.
Mirror-Polished Brass Cup Washers
High-gloss mirror-polished or lacquered finish for visible architectural and decorative applications — door hardware, signage, boat fittings, and premium furniture.
Material Grades and International Equivalents
| Alloy | India (IS) | USA (ASTM/UNS) | UK (BS) | Germany (DIN) | Application |
|---|---|---|---|---|---|
| Cartridge Brass (70/30) | IS 410 | UNS C26000 / ASTM B19 | BS 2870 CZ106 | DIN CuZn30 | Deep drawn/stamped cup washers |
| Free Cutting Brass | IS 319 Type I | UNS C36000 / ASTM B16 | BS CZ121 | DIN CuZn39Pb3 | Machined cup washers, turned |
| Gilding Metal (95/5) | — | UNS C21000 / ASTM B36 | BS CZ101 | DIN CuZn5 | Premium decorative, gold-tone appearance |
| Admiralty Brass | IS 291 | UNS C44300 / ASTM B171 | BS CZ111 | DIN CuZn28Sn | Marine environments |
Sizes and Specifications Available
- Screw Size: #4 (#8, #10, #12, #14) Imperial; M3, M4, M5, M6, M8, M10 Metric
- Countersink Angle: 82° (US standard flat head), 90° (metric standard)
- Outside Diameter: 0.375″ to 1.5″ (9.5mm to 38mm)
- Thickness: 0.032″ to 0.062″ (0.8mm to 1.6mm)
- Finish Options: Natural brass, polished brass, satin brass, nickel-plated, chrome-plated, antique brass
- Packaging: Poly bags, boxes, or bulk in customer-specified quantities
Applications of Brass Cup Washers
- Woodworking & Cabinetry – Flush screw heads in hardwood panels, drawer fronts, face frames
- Marine & Boat Building – Deck fittings, teak decking, stainless screw dressing
- Architectural Hardware – Door plates, signage, window hardware, handrails
- Musical Instruments – Guitar hardware, violin fittings, woodwind instrument assembly
- Furniture Manufacturing – Premium furniture, antique reproductions, decorative joinery
- Outdoor & Landscaping – Decking, pergolas, garden furniture hardware
Why Choose Jamnagar Brass Components for Brass Cup Washers?
- Precision Stamping – Consistent countersink angle and OD dimension in every piece for a perfect flush fit.
- Wide Size Range – Full imperial and metric size programs available from stock or to order.
- Superior Surface Finish – Barrel-polished for burr-free surfaces; plating options for premium appearance.
- Cost-Effective Bulk Pricing – Competitive factory-direct pricing for US hardware distributors and e-commerce sellers.
- Custom Sizes – Non-standard OD, ID, or countersink angles for OEM applications.
- Reliable Delivery – Regular sea freight shipments to US East and West Coast ports.
Frequently Asked Questions (FAQ)
Q: What is the difference between a cup washer and a flat washer?
A: A flat washer is a plain disc with a hole; it distributes load but sits flat on the surface. A cup washer (finishing washer) has a countersunk recess that accepts a flat-head screw head, allowing the screw to sit flush or slightly recessed within the washer for a decorative finish.
Q: Can brass cup washers be used outdoors?
A: Yes. Lacquered or nickel-plated brass cup washers perform well in sheltered outdoor applications. For fully exposed marine environments, we recommend our Naval brass or silicone-bronze cup washers.
Q: Do you supply brass cup washers to match stainless steel screw heads?
A: Yes. We supply chrome-plated or satin nickel brass cup washers that complement the appearance of stainless steel screws, popular in marine decking and architectural metalwork.
Get a Quote for Brass Cup Washers
Contact Jamnagar Brass Components for a competitive quotation on brass cup washers and finishing washers for your project or distribution requirements.
📧 Email: sales@jambrass.com
🌐 Website: www.jambrass.com