Bronze Washers, Phosphor Bronze Washers

Bronze Washers & Phosphor Bronze Washers – ASTM Certified | Trusted by US Engineers & OEMs

When American engineers specify phosphor bronze washers for spring applications, thrust bearings, or electrical contacts, they need a supplier who understands ASTM material standards, delivers consistent mechanical properties, and ships reliably to US ports. Conex Screws and Fasteners has been that supplier for the US market for over 30 years. Our Phosphor Bronze Washers and Bronze Washers are manufactured from ASTM B139 and ASTM B103 certified strip — covering grades C51000 (PB101) and C52100 (PB102) — with full mill test certificates, RoHS declarations, and export documentation that clears US Customs seamlessly.

From defense contractors in Virginia to electronics manufacturers in Silicon Valley, from hydraulic equipment OEMs in the Midwest to marine hardware distributors on the Gulf Coast — US buyers across every industry rely on Conex for precision bronze washers that perform as engineered, lot after lot.

Why US Buyers Specify Conex Phosphor Bronze Washers

• ASTM B139 / B103 Certified: Material sourced from certified mills; MTCs with full chemistry and mechanical properties provided on every order.
• All Tempers Available: Annealed (O), Quarter Hard (H01), Half Hard (H02), Hard (H04), and Spring (H08) — matching whatever your engineering spec calls out.
• Imperial & Metric Sizing: ASME B18.22.1 inch-series dimensions available alongside metric (DIN 125 / ISO 7089).
• India-Origin Tariff Advantage: Indian-origin bronze parts generally avoid Section 301 tariffs applied to Chinese goods — same quality, better total landed cost.
• Pre-Shipment Inspection: SGS, BV, or Intertek inspection available for US buyers with strict incoming quality requirements.
• US-Standard Documentation: COO (India), ASTM MTC, RoHS declaration, COC, SDS — everything your procurement and compliance teams require.

What Are Phosphor Bronze Washers?

Phosphor bronze washers are precision-pressed flat washers manufactured from phosphor bronze alloy (copper-tin-phosphorus), recognized in the US under ASTM designations C51000 (5% tin) and C52100 (8% tin). The phosphorus addition significantly improves strength, hardness, and fatigue life over standard brass — making these washers the preferred choice when standard brass or steel won’t hold up. They are widely used in US industries as thrust washers, bearing washers, spring contact washers, sealing washers, and electrical contact washers. Bronze washers more broadly include tin bronze (C90700), aluminum bronze (C61300), and silicon bronze (C65500) — each available from Conex to ASTM standards.

Key Engineering Features

• High Fatigue Strength: Phosphor bronze (especially H02 and H08 temper) sustains millions of cycles without fatigue failure — critical for dynamic and oscillating assemblies.
• Excellent Spring-Back: Used as spring washers and Belleville-style components in electrical and mechanical assemblies across US aerospace, defense, and industrial OEM sectors.
• Good Electrical Conductivity: 15–20% IACS — suitable for electrical contact and grounding applications per NEC and NEMA standards.
• Non-Magnetic: Safe near sensitive instruments, MRI equipment, and avionics per US aerospace and medical device requirements.
• Corrosion Resistant: Performs in marine (ASTM B139 marine-grade alloys), industrial, and moderate chemical environments — preferred in coastal US states.
• Custom Temper & Profile: Specify your exact temper code (ASTM H01/H02/H04/H08) and we press to that mechanical property band.

ASTM Material Grades & US / International Cross-Reference

US Imperial & Metric Size Chart – Bronze Washers

All dimensions available in inches (ASME B18.22.1) or millimeters (ISO 7089 / DIN 125) per customer specification.

Performance Metrics (ASTM C51000 – Phosphor Bronze Grade A)

• Tensile Strength: 55,000–100,000 psi (annealed to spring temper H08)
• Yield Strength (0.2% offset): 22,000–90,000 psi depending on temper
• Hardness: 60–200 HV (Vickers) / 60–95 HRB (Rockwell B)
• Elongation: 35% (annealed O) to 3% (spring H08)
• Electrical Conductivity: 15% IACS (C51000) / 13% IACS (C52100)
• Fatigue Strength: 22,000 psi at 10⁸ cycles (C51000, H02 temper)
• Operating Temperature: -325°F to +300°F (-200°C to +150°C)
• Dimensional Tolerance: ±0.002″ (±0.05 mm) standard

Our Technical Expertise — 30 Years of Bronze Pressing for US Buyers

Conex Screws and Fasteners has operated precision bronze pressing operations for US customers since the early 1990s. We understand that US OEM buyers — whether in aerospace, defense, electronics, or industrial equipment — need more than just a washer: they need a documented material trail, a supplier who understands ASTM designation systems, and a manufacturing partner who won’t substitute material grades without authorization. Our in-house quality lab performs incoming strip inspection, in-process hardness verification, and final dimensional sampling to ANSI/ASQ Z1.4 sampling plans. Our American customers receive the same quality assurance they’d expect from a US-based vendor, at the cost advantage of an Indian manufacturer.

Related US Search Terms

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US-Compliant Export Packaging

Bronze and phosphor bronze washers are packed in zip-seal polybags labeled with ASTM grade (e.g., C51000-H02), size in inches (and mm), temper, quantity, and lot number for full material traceability. Outer cartons meet US ISPM-15 phytosanitary requirements. Each shipment includes ASTM MTC, RoHS declaration, packing list, and commercial invoice in USD. We can also provide COC (Certificate of Conformance) signed by our QC manager.

Why US Buyers Choose Conex Over Domestic or Other Overseas Sources

• ASTM-Genuine Certified Material: Not just labeled — we provide real, verifiable MTCs from Indian mills with ASTM chemistry and mechanical data.
• Full Temper Range: O, H01, H02, H04, H08 — in stock and to order. Few overseas suppliers carry the full ASTM temper range.
• India-Origin Tariff Benefit: Avoid Section 301 China tariffs — Indian phosphor bronze washers import duty-free or at standard MFN rates.
• Custom Sizes & Profiles: OD, ID, thickness, profile — we tool in-house and deliver to your drawing in inches or millimeters.
• Responsive US-Friendly Communication: English-speaking team, US business hour overlap, same-day email response, USD invoicing.
• Third-Party Inspection: SGS/BV/Intertek pre-shipment inspection welcomed and coordinated at our facility.

What Separates Conex from Other Bronze Washer Manufacturers

Conex’s 30-year focus on the US export market means we think like an American QC engineer when manufacturing bronze washers. We maintain documented control plans, SPC on critical dimensions, and retain first-off and last-off samples from every production run for traceability in case of future audit or warranty claim. When a US buyer calls with a non-conformance question six months after delivery, our lot-level records can answer it. This level of documentation discipline — standard practice for US defense and aerospace supply chains — is rare among overseas pressed parts manufacturers, but it’s how Conex has maintained 30-year US customer relationships.

US Industry Applications

• Defense & Aerospace (ITAR-aware): Non-magnetic phosphor bronze washers for avionics, communications hardware, and weapons systems components
• Electronics & PCB Assembly (Silicon Valley, Austin TX, RTP NC): Phosphor bronze spring washers and contact washers for PCB hardware and connector assemblies
• Hydraulic & Pneumatic Equipment (Midwest OEM belt): Bronze thrust washers and sealing washers for fluid power systems
• Marine & Offshore (Gulf Coast, Pacific NW): Aluminum bronze and silicon bronze washers for seawater-resistant assemblies
• Industrial Machinery: Tin bronze thrust pads and bearing washers for rotating equipment
• Medical Devices: Non-magnetic, biocompatible phosphor bronze washers for MRI-safe and non-sparking environments

Frequently Asked Questions – US Buyers

Q1. Do your phosphor bronze washers meet ASTM B139 specifications?

Yes. We manufacture from ASTM B139-compliant C51000 strip (Grade A, 5% tin) and ASTM B103-compliant C52100 (Grade C, 8% tin). Full MTCs confirming ASTM chemistry and mechanical properties are provided with every shipment.

Q2. Can you supply phosphor bronze washers in ASME B18.22.1 inch dimensions?

Yes. We manufacture to ASME B18.22.1 (inch series) plain washer dimensions as standard, or to customer drawings in either inches or millimeters.

Q3. What ASTM temper codes are available?

We supply O (annealed), H01 (quarter hard), H02 (half hard), H04 (hard), and H08 (spring) tempers per ASTM B139/B103. Specify your required temper when ordering.

Q4. Are phosphor bronze washers subject to Section 301 tariffs from India?

No. Section 301 tariffs primarily apply to Chinese-origin goods. Indian-origin phosphor bronze washers are imported at standard MFN duty rates under HTS Chapter 74. Consult your customs broker for your specific HTS classification.

Q5. Can you supply DFARS-compliant bronze washers?

We can supply bronze washers with full material documentation and country-of-origin certification. For DFARS-specific sourcing requirements, please consult with your contracting officer — we support the documentation process.

Q6. What is the MOQ for US buyers?

MOQ is 1,000 pieces per size/temper combination for standard items. We are flexible for trial orders — contact us to discuss.

Q7. Do you provide COC (Certificate of Conformance) documents?

Yes. We provide a signed COC with every shipment confirming the goods meet specified ASTM grade, temper, and dimensional requirements.

Q8. What is the lead time from order to US port delivery?

Manufacturing: 7–14 days. Sea freight to US West Coast: 18–25 days. Total: approximately 4–6 weeks from PO to delivery. Air freight: 5–7 business days transit.

Q9. Can you supply aluminum bronze washers (ASTM C61300) for offshore use?

Yes. Aluminum bronze (C61300 / C63000) washers for marine and offshore applications are available. Please specify application details for grade recommendation.

Q10. Do you accept Letters of Credit (LC) from US buyers?

Yes. We accept T/T wire transfer and irrevocable LC at sight. For new buyers, standard terms are 30% advance / 70% before shipment. Established buyers may qualify for open account.

Q11. Can you supply phosphor bronze spring washers (Belleville type)?

Yes. We manufacture phosphor bronze Belleville (disc spring) washers, wave washers, and curved washers in H04/H08 spring temper to customer drawings.

Q12. Are your bronze washers suitable for use in US food processing equipment?

Silicon bronze (C65500) and certain tin bronze alloys are used in food-adjacent applications. For FDA-regulated food contact applications, please specify and we will advise on the appropriate alloy and finish.

Q13. Can you do pre-production first-article inspection (FAI) reports?

Yes. FAI reports with full dimensional layout per AS9102 or customer format are available for aerospace and precision engineering customers.

Q14. What US ports do you ship to?

We ship regularly to Los Angeles/Long Beach, New York/NJ, Baltimore, Savannah, Houston, and Seattle. We work with US freight forwarders of your choice or can recommend established consolidators.

Q15. How do I request a quote for phosphor bronze washers for our US company?

Send us your ASTM grade (C51000 or C52100), temper, size (inches or mm), quantity, and delivery port. We respond with a USD-denominated FOB/CIF quotation within 24 hours.

Customer Testimonials

“We source phosphor bronze C51000 H02 washers from Conex for our precision instrumentation assemblies. Their ASTM MTCs are always complete and accurate, dimensions are consistent lot to lot, and their response time is excellent. A genuinely reliable overseas supplier.”

— Robert Schäfer, Quality Engineer, Precision Instruments OEM, California, USA

“Conex delivered custom ASTM B139 C52100 thrust washers to our exact inch-dimension drawing in H02 temper — exactly what our hydraulic pump spec called for. Lead time was shorter than our domestic quote and the price was highly competitive. We’ve placed four repeat orders since.”

— David Nguyen, Purchasing Manager, Hydraulic Equipment OEM, Ohio, USA

Glossary of US Trade Terms

ASTM B139

American standard for phosphor bronze rod, bar, and shapes — C51000 (5% tin, Grade A) is the primary alloy for spring washers and contacts.

ASTM B103

American standard for phosphor bronze plate, sheet, strip, and rolled bar — covers C51000, C52100, and C54400 alloys in various tempers.

Temper (ASTM H-code)

Degree of cold working: O=annealed (softest), H01=quarter hard, H02=half hard, H04=hard, H08=spring (hardest). Higher temper = higher strength and hardness, lower ductility.

ASME B18.22.1

US standard governing inch-series plain washer dimensions — Type A (narrow) and Type B (wide) series.

DFARS

Defense Federal Acquisition Regulation Supplement — US Department of Defense procurement rules that may restrict the use of specialty metals (including certain bronze alloys) to US or qualifying country origin.

Section 301 Tariffs

Additional tariffs applied to Chinese-origin goods — Indian phosphor bronze washers are not subject to these tariffs under standard MFN treatment.

MFN (Most Favored Nation)

The standard US import tariff rate applied to goods from countries with normal trade relations — India qualifies for MFN treatment.

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Ready to Source? Request a US-Specific Quote Today!

Join the growing community of US engineers and procurement professionals who trust Conex Screws and Fasteners for ASTM-certified bronze and phosphor bronze washers. India-origin, tariff-advantaged, fully documented, and delivered to your US port.

📧 Email your RFQ — ASTM grade, temper, size (inches or mm), quantity, and destination port. USD quote in 24 hours.

✅ ASTM B139/B103 certified  |  ✅ All tempers O to H08  |  ✅ Inch & metric sizes  |  ✅ India-origin (Section 301 exempt)  |  ✅ Pre-shipment inspection available