Home | Metric Copper Washers - Sealing & Conductive Flat Washers

Metric Copper Washers - Sealing & Conductive Flat Washers

Metric copper washers are valued for their superior sealing performance, electrical conductivity, and corrosion resistance in metric fastener applications including hydraulic fittings, plumbing connections, and electrical assemblies. Superior Washer & Gasket Corp supplies metric copper washers in standard DIN and ISO sizes and produces custom metric copper sealing washers to your specifications.

As an ISO 9001:2015 certified metal washer manufacturer, we maintain inventory of metric copper washers for fast delivery and offer custom stamping for non-standard metric sizes. All products are made in the U.S.A. with complete material traceability.

  • Metric copper washers for hydraulic and sealing applications
  • DIN and ISO standard sizes in stock
  • Custom metric copper sealing washers available
  • ISO 9001:2015 certified manufacturing
  • Made in the U.S.A.

Showing 151–200 of 400 products

SKU ID (MM) OD (MM) Thickness (MM) Material ID MM TOL OD MM TOL Quantity

175-2303

ID (MM) 8.306
OD (MM) 12.751
Thickness (MM) 1.626
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2304

ID (MM) 8.357
OD (MM) 12.649
Thickness (MM) 0.787
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2305

ID (MM) 8.357
OD (MM) 13.868
Thickness (MM) 0.279
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2306

ID (MM) 8.357
OD (MM) 14.326
Thickness (MM) 0.635
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2307

ID (MM) 8.357
OD (MM) 14.326
Thickness (MM) 1.575
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2308

ID (MM) 8.382
OD (MM) 14.224
Thickness (MM) 0.813
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2309

ID (MM) 8.382
OD (MM) 14.249
Thickness (MM) 0.229
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2310

ID (MM) 8.407
OD (MM) 12.7
Thickness (MM) 1.575
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2311

ID (MM) 8.407
OD (MM) 14.3
Thickness (MM) 0.787
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2312

ID (MM) 8.407
OD (MM) 15.799
Thickness (MM) 1.016
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2313

ID (MM) 8.433
OD (MM) 14.249
Thickness (MM) 0.813
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2314

ID (MM) 8.433
OD (MM) 14.275
Thickness (MM) 1.295
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2315

ID (MM) 8.585
OD (MM) 19.05
Thickness (MM) 1.651
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2316

ID (MM) 8.636
OD (MM) 14.249
Thickness (MM) 0.787
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2317

ID (MM) 8.738
OD (MM) 14.122
Thickness (MM) 0.762
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2318

ID (MM) 8.738
OD (MM) 14.224
Thickness (MM) 0.381
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2319

ID (MM) 8.738
OD (MM) 22.352
Thickness (MM) 0.813
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2320

ID (MM) 8.788
OD (MM) 17.399
Thickness (MM) 1.524
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2321

ID (MM) 8.814
OD (MM) 12.725
Thickness (MM) 0.787
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2322

ID (MM) 8.814
OD (MM) 18.999
Thickness (MM) 1.6
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2323

ID (MM) 9.22
OD (MM) 14.3
Thickness (MM) 0.686
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2324

ID (MM) 9.246
OD (MM) 11.938
Thickness (MM) 0.508
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2325

ID (MM) 9.525
OD (MM) 15.85
Thickness (MM) 1.6
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2326

ID (MM) 9.55
OD (MM) 14.224
Thickness (MM) 0.813
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2327

ID (MM) 9.576
OD (MM) 14.199
Thickness (MM) 1.6
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2328

ID (MM) 9.601
OD (MM) 13.589
Thickness (MM) 0.406
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2329

ID (MM) 9.601
OD (MM) 14.275
Thickness (MM) 0.381
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2330

ID (MM) 9.601
OD (MM) 14.275
Thickness (MM) 0.787
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2331

ID (MM) 9.601
OD (MM) 22.174
Thickness (MM) 0.787
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2332

ID (MM) 9.627
OD (MM) 12.675
Thickness (MM) 0.813
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2333

ID (MM) 9.627
OD (MM) 14.275
Thickness (MM) 0.838
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2334

ID (MM) 9.627
OD (MM) 15.723
Thickness (MM) 1.6
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2335

ID (MM) 9.652
OD (MM) 15.088
Thickness (MM) 1.575
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2336

ID (MM) 9.652
OD (MM) 15.57
Thickness (MM) 1.6
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2337

ID (MM) 9.652
OD (MM) 17.475
Thickness (MM) 0.838
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2338

ID (MM) 9.703
OD (MM) 13.538
Thickness (MM) 0.813
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2339

ID (MM) 9.754
OD (MM) 19.177
Thickness (MM) 1.549
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2340

ID (MM) 9.779
OD (MM) 15.85
Thickness (MM) 1.575
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2341

ID (MM) 9.83
OD (MM) 12.395
Thickness (MM) 1.6
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2342

ID (MM) 9.855
OD (MM) 22.225
Thickness (MM) 1.803
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2343

ID (MM) 9.906
OD (MM) 14.3
Thickness (MM) 1.549
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2344

ID (MM) 9.906
OD (MM) 14.707
Thickness (MM) 0.813
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2345

ID (MM) 9.957
OD (MM) 15.875
Thickness (MM) 0.813
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2346

ID (MM) 9.957
OD (MM) 16.002
Thickness (MM) 1.016
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2347

ID (MM) 9.957
OD (MM) 25.4
Thickness (MM) 1.651
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2348

ID (MM) 9.982
OD (MM) 12.675
Thickness (MM) 0.813
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2349

ID (MM) 10.008
OD (MM) 14.249
Thickness (MM) 0.813
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2350

ID (MM) 10.008
OD (MM) 14.275
Thickness (MM) 0.813
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2351

ID (MM) 10.008
OD (MM) 14.326
Thickness (MM) 1.6
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

175-2352

ID (MM) 10.008
OD (MM) 15.85
Thickness (MM) 1.549
Material Copper
ID MM TOL 0.127
OD MM TOL 0.127
Quantity

Metric Copper Washer Frequently Asked Questions

Below are answers to some of the most common questions about metric copper washers.

What are metric copper washers?
Metric copper washers are flat sealing and conductive washers dimensioned in millimeters for use with metric fasteners. Superior Washer manufactures metric copper washers to DIN and ISO standard sizes and custom metric dimensions, with over 400 configurations in stock. Copper's softness and malleability make metric copper washers ideal for creating leak-proof seals in metric hydraulic fittings, plumbing connections, and fuel systems.

What are metric copper washers used for?
Metric copper washers are most commonly used as crush or sealing washers in metric hydraulic fittings, drain plugs, banjo bolt connections, and plumbing joints where a leak-proof metal-to-metal seal is required. They are also used in electrical assemblies as conductive spacers and in applications requiring a soft, non-galling interface between metric fasteners and mating surfaces.

What size range are your metric copper washers available in?
Our metric copper catalog covers ID sizes from approximately 1.9 mm through 20.7 mm and OD sizes from approximately 3.9 mm through 38.2 mm, in thicknesses from 0.127 mm through 3.28 mm. This range supports common metric hydraulic and plumbing fitting sizes across M3 through M20 and beyond.

Can you produce custom metric copper washers?
Yes. We manufacture custom metric copper sealing washers to your exact millimeter OD, ID, and thickness specifications. Contact us via the Quick Quote form or call NY (631) 273-8282 or SC (803) 366-3250.

Are your metric copper washers made in the USA?
Yes. All metric copper washers are manufactured in the United States under our ISO 9001:2015 certified Quality Management System with full material traceability. Material certifications are available upon request.

Need copper in imperial sizing instead? We also stock copper and other materials in SAE and USS dimensions. Browse the full flat washers catalog to compare all sizing and material options.