Product Overview
USS Flat Washers (ANSI B18.22.1) – Manufactured from premium zinc-plated carbon steel, available in standard sizes from 1/4″ to 1-1/8″. Designed for use with USS bolts, hex nuts, and spring washers, ensuring reliable load distribution and surface protection. As an experienced OEM flat washer manufacturer, we offer custom-size USS washer solutions tailored to your specifications. Factory-direct supply from China ensures ANSI-compliant quality and highly competitive pricing. Ideal for construction, heavy machinery, and automotive applications, our flat washers feature superior corrosion resistance with durable zinc plating. Bulk quantities available with customizable packaging. Contact us today for samples or a quote.
Technical Specifications
| Standard | ANSI B18.22.1 (US Standard for Flat Washers) |
| Material | Carbon Steel (Grade 1018 or equivalent) |
| Surface Finish | Zinc Plated (Electroplated) / Complies with ASTM B633 Type II or equivalent |
| Salt Spray Test | 72-96 hours (Coating thickness typically ≥8μm) |
| Hardness | HRB 70-85 (Rockwell B Scale) |
| Tensile Strength | ≥60,000 PSI (≈414 MPa) |
| Operating Temperature | -30°C to +120°C (Zinc coating stability range) |
| Available Sizes | #1/4, #5/16, #3/8, #7/16, #1/2, #5/8, #3/4, #7/8, #1, #1-1/8 (zinc plating standard) |
Flat washers sizes chart
| Size | Inner Diameter (ID) | Outer Diameter (OD) | Thickness | Zinc Plating Tolerance |
|---|---|---|---|---|
| #1/4 | 0.266″ (6.76 mm) | 0.625″ (15.88 mm) | 0.065″ (1.65 mm) | ID: ±0.005″, OD: ±0.010″ |
| #5/16 | 0.328″ (8.33 mm) | 0.750″ (19.05 mm) | 0.065″ (1.65 mm) | Same as above |
| #3/8 | 0.391″ (9.93 mm) | 0.875″ (22.23 mm) | 0.065″ (1.65 mm) | Same as above |
| #7/16 | 0.453″ (11.51 mm) | 1.000″ (25.40 mm) | 0.083″ (2.11 mm) | Same as above |
| #1/2 | 0.516″ (13.10 mm) | 1.125″ (28.58 mm) | 0.083″ (2.11 mm) | Same as above |
| #5/8 | 0.641″ (16.28 mm) | 1.375″ (34.93 mm) | 0.109″ (2.77 mm) | Same as above |
| #3/4 | 0.766″ (19.46 mm) | 1.500″ (38.10 mm) | 0.109″ (2.77 mm) | Same as above |
| #7/8 | 0.891″ (22.63 mm) | 1.750″ (44.45 mm) | 0.125″ (3.18 mm) | Same as above |
| #1 | 1.031″ (26.19 mm) | 2.000″ (50.80 mm) | 0.125″ (3.18 mm) | Same as above |
| #1-1/8 | 1.156″ (29.36 mm) | 2.250″ (57.15 mm) | 0.140″ (3.56 mm) | Same as above |
Application Scenarios
USS Flat Washers (ANSI B18.22.1) are essential for heavy-duty industrial connections. Available in zinc-plated carbon steel or stainless steel 304 for superior corrosion resistance.
Infrastructure Projects
Ideal for bridge construction, transmission towers, and railway track fastenings where vibration resistance is crucial
Energy Sector
Commonly used in wind turbine assemblies, oil rig structures, and power plant equipment installations
Transportation Equipment
Critical for heavy truck chassis, trailer hitches, and agricultural machinery where durable fastening is required
Industrial Maintenance
Perfect for machinery rebuilds and equipment repairs in manufacturing facilities
Frequently Asked Questions
Can you provide material certifications?
Yes, all washers come with Mill Test Certificates (MTC). Carbon steel washers meet ASTM A307, stainless 304 meets ASTM A666.
What’s the lead time for bulk orders?
Stock items ship in 7-30 days. Custom sizes require 15-40 days production (50,000pcs+ quantities).
Do you offer private labeling?
Absolutely – we provide OEM services including custom packaging, laser etching, and branded bags/boxes.
How do you ensure quality consistency?
Our China factory has: ISO 9001:2015 certification, in-house metallurgical lab, and 100% dimensional inspection.
Can you match competitor pricing?
We regularly benchmark against market prices. Share your target price – we’ll optimize costs through material selection or packaging.
Do you provide samples?
Free samples available (customer pays shipping). Express samples ready in 48hrs for urgent projects.
Our Manufacturing Facility and Products
Direct Supply from Chinese Factory
Welcome to Handan Quanfan Metal Products Co., Ltd., a leading China manufacturer specializing in fasteners including self drilling screws, drywall screws, stainless steel bolts, self tapping screws, and grade 5 nuts.
Contact Us
Need more information about our USS Flat Washers or have special requirements? Our technical sales team is ready to serve customers worldwide.
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