STAINLESS STEEL WASHERS
Company Profile
Shandong Boltec Metal Industry Co., Ltd. is a professional manufacturer specializing in stainless steel fasteners, with over 15 years of industry experience. We are committed to providing reliable, durable and cost-effective fastening solutions to global customers. Our stainless steel washers are precision-engineered to distribute load, prevent surface damage, and ensure secure fastening in all applications.
Product Features
Superior Material Quality: Made from premium 304/316 stainless steel with excellent corrosion resistance and mechanical properties. Alternative grades such as 410 and Duplex are also available.
Precision Manufacturing: Advanced stamping and punching equipment ensures consistent dimensions, smooth edges, and proper flatness for reliable performance.
Surface Finish Options: Passivation, Ruspert, Dacromet, Procote, and other surface treatments available to enhance corrosion resistance and extend service life.
Wide Product Range: Comprehensive offerings including Flat Washers, Spring Lock Washers, Tooth Lock Washers, Square Washers, Fender Washers, and more.
Customization Capability: Flexible production to meet specific customer requirements for size, thickness, material grade, and packaging.
More Information for Stainless Steel Washers
| Item | Details |
| Standards | DIN 125 / DIN 127 / DIN 9021 / DIN 6797 / DIN 6798 / DIN 433 / DIN 7349 / DIN 440, ISO 7089 / ISO 7090 / ISO 7091 / ISO 7092 / ISO 7093 / ISO 7094, ANSI/ASME B18.21.1, JIS B1256 |
| Material | Stainless Steel 304 (A2), 316 (A4), 410, 316L, Duplex 2205 |
| Hardness | Typically ≤ 200 HV for flat washers, spring washers heat-treated to achieve spring properties |
| Size Range | M2 – M64 (Metric), #0 – 2" (Inch) |
| Thickness Options | Standard thickness, light series, heavy series (depending on standard) |
| Surface Finish | Plain (Bright), Passivated, Polished, Ruspert, Dacromet, Procote, Zinc Plated |
| Customized Products | Lead Time: 30-50 days for busy season, 20-30 days for slack season (depending on complexity) |
| Standard Products | DIN/ISO norm products: 15-30 days |
| Packaging | Small box in carton, then Euro EPAL pallet / Poly bags / Color box / Bucket / DIY packaging upon customer demand |
Washer Types Available
Flat Washers (Plain Washers)
| Type | Description | Standards | Typical Use |
| Type A (Small OD) | Normal outside diameter, standard thickness | DIN 125A, ISO 7089 | General purpose, standard bolt clearance |
| Type B (Small OD) | Chamfered edge version | DIN 125B, ISO 7090 | General purpose with smoother edge |
| Large OD (Type C) | Larger outside diameter for increased load distribution | DIN 9021, ISO 7093 | Soft materials, oversized holes |
| Extra Large OD | Very large outside diameter for maximum load distribution | ISO 7094 | Wood, plastic, structural steel |
| Narrow Series | Reduced outside diameter for limited space | DIN 433, ISO 7092 | Precision assemblies, counterbored holes |
| Heavy Series | Extra thickness for heavy-duty applications | DIN 7349 | High-load applications, structural use |
Lock Washers
| Type | Description | Standards | Typical Use |
| Spring Lock Washer | Split ring design creates tension to prevent loosening | DIN 127A, DIN 127B | General vibration resistance |
| Wave Spring Washer | Wavy design provides spring pressure and vibration damping | DIN 137B | Bearing preload, noise reduction |
| Curved Spring Washer | Curved design for light spring applications | DIN 137A | Light preload applications |
Tooth Lock Washers
| Type | Description | Standards | Typical Use |
| External Tooth | Teeth on outer edge bite into bearing surface | DIN 6798A, DIN 6798J | Maximum locking, larger bearing surface |
| Internal Tooth | Teeth on inner edge, hidden under bolt head | DIN 6797A, DIN 6797J | Aesthetic appearance, limited space |
| Combination Internal/External | Teeth on both edges for maximum locking | DIN 6797J, DIN 6798J | Extra security applications |
| Countersunk Tooth | Designed for countersunk screw heads | DIN 6798C | Flush mounting applications |
Specialty Washers
| Type | Description | Standards | Typical Use |
| Square Washer | Square shape for wood and structural applications | DIN 436, DIN 440 | Wood construction, timber connections |
| Fender Washer | Very large OD relative to ID, also known as mudguard washer | DIN 9021 (similar) | Thin materials, oversized holes |
| Taper Washer | Wedge-shaped for leveling flange beams and channels | DIN 434, DIN 435 | Steel construction, I-beam connections |
| Countersunk Washer | Beveled face for countersunk screws | DIN 74 | Flush screw installations |
| Insulating Washer | Non-metallic for electrical isolation (available upon request) | Custom | Electrical isolation, anti-vibration |
| Belleville Washer | Conical disc spring for high spring loads | DIN 6796 | Thermal expansion compensation, high preload |
Why Choose Our Stainless Steel Washers?
Precise Dimensions: Strict tolerances on ID, OD, and thickness ensure proper fit with matching bolts
Burr-Free Edges: Deburred surfaces prevent damage to mating parts and injury during handling
Consistent Hardness: Proper material selection and processing ensures washers perform as intended
Full Traceability: Material certifications available upon request
Corrosion Resistance: Salt spray testing available to verify performance in harsh environments
Global Standards Compliance: Manufactured to meet DIN, ISO, ANSI, and JIS specifications
Quality Assurance
ISO 9001:2015 certified quality management system
Strict raw material inspection with material certificates provided
100% dimensional inspection including ID, OD, and thickness gauging
Hardness testing for spring washers to verify proper heat treatment
Surface finish inspection for passivation quality
Third-party testing available upon request (SGS, BV, TUV)
Compliance with international standards: DIN, ISO, ANSI, JIS
Washer Selection Guide
| Application | Recommended Washer Type | Purpose |
| General assembly, standard bolts | Flat Washer (DIN 125, ISO 7089) | Load distribution, surface protection |
| Soft materials (wood, plastic, aluminum) | Large OD Flat Washer (DIN 9021) | Prevent pull-through, distribute load |
| Vibration-prone equipment | Spring Lock Washer (DIN 127) | Prevent loosening from vibration |
| Electrical grounding | External Tooth Lock Washer (DIN 6798) | Cut through paint/coatings for ground path |
| Oversized or slotted holes | Large OD Flat Washer (ISO 7094) | Bridge oversize openings |
| Countersunk screws | Countersunk Washer (DIN 74 compatible) | Flush mounting with proper support |
| Structural steel (I-beams, channels) | Taper Washer (DIN 434, DIN 435) | Compensate for flange slope |
| High-temperature with vibration | All Metal Lock Washer (DIN 6796) | Spring tension at high temperatures |
| Limited space, precision assemblies | Narrow Series Flat Washer (DIN 433) | Fit in tight spaces, counterbored holes |
| Marine environments | A4 (316) Stainless Steel Washers | Maximum corrosion resistance |
Washer Dimensions (Metric - Select Sizes)
Flat Washers - DIN 125A / ISO 7089
| Size | Inside Diameter (mm) | Outside Diameter (mm) | Thickness (mm) |
| M3 | 3.2 | 7 | 0.5 |
| M4 | 4.3 | 9 | 0.8 |
| M5 | 5.3 | 10 | 1.0 |
| M6 | 6.4 | 12 | 1.6 |
| M8 | 8.4 | 16 | 1.6 |
| M10 | 10.5 | 20 | 2.0 |
| M12 | 13.0 | 24 | 2.5 |
| M16 | 17.0 | 30 | 3.0 |
| M20 | 21.0 | 37 | 3.0 |
| M24 | 25.0 | 44 | 4.0 |
| M30 | 31.0 | 56 | 5.0 |
| M36 | 37.0 | 66 | 6.0 |
Large OD Flat Washers - DIN 9021 / ISO 7093
| Size | Inside Diameter (mm) | Outside Diameter (mm) | Thickness (mm) |
| M3 | 3.2 | 9 | 0.8 |
| M4 | 4.3 | 12 | 1.0 |
| M5 | 5.3 | 15 | 1.2 |
| M6 | 6.4 | 18 | 1.6 |
| M8 | 8.4 | 24 | 2.0 |
| M10 | 10.5 | 30 | 2.5 |
| M12 | 13.0 | 37 | 3.0 |
| M16 | 17.0 | 50 | 4.0 |
| M20 | 21.0 | 60 | 5.0 |
| M24 | 25.0 | 72 | 6.0 |
FAQ – Stainless Steel Washers
Q1: What is the purpose of a washer?
A: Washers serve multiple functions: distributing load over a larger area, protecting the surface from damage, providing spring tension to prevent loosening, spanning oversized holes, and acting as spacers.
Q2: What is the difference between DIN 125 and DIN 9021 washers?
A: DIN 125 (ISO 7089) is a standard flat washer with normal outside diameter. DIN 9021 (ISO 7093) is a large outside diameter washer that provides greater load distribution, ideal for soft materials or oversized holes.
Q3: How do spring lock washers work?
A: Split spring lock washers compress when tightened, creating spring tension that maintains friction between the bolt head/nut and the mating surface, resisting loosening from vibration.
Q4: When should I use tooth lock washers?
A: Tooth lock washers are ideal when you need maximum vibration resistance or when electrical continuity through the joint is required. External tooth washers provide better locking, while internal tooth washers are more aesthetic.
Q5: Do I need a washer with a flange bolt or flange nut?
A: No, flange bolts and flange nuts have an integrated washer face and do not typically require separate washers unless additional load distribution or spacing is needed.
Q6: Can stainless steel washers cause galvanic corrosion?
A: When used with other stainless steel fasteners, there is no issue. When connecting dissimilar metals, consider using insulating washers or consult corrosion guidelines for your specific materials.
Q7: What is the difference between A2 and A4 stainless steel washers?
A: A2 (304) is standard grade for general applications. A4 (316) contains molybdenum, providing superior corrosion resistance for marine and chemical environments.
Q8: Do you provide washers for inch-sized bolts?
A: Yes, we supply washers in inch sizes (ANSI/ASME B18.21.1) including USS and SAE series.
Q9: What is your MOQ (Minimum Order Quantity)?
A: Our MOQ is generally 500 kg for standard washers. For customized items, please contact us to discuss your requirements.
Q10: Can you manufacture non-standard washer sizes?
A: Yes, we can produce custom washers with specific ID, OD, and thickness dimensions to meet your unique application requirements.
Q11: Do you offer samples?
A: Yes, samples are available upon request. Please contact our sales team for sample orders.
Installation Tips
Flat Washer Orientation: Flat washers are non-directional; either side can face the bolt head or nut
Spring Washer Orientation: The split ends should face clockwise when looking at the nut (opposite tightening direction)
Tooth Washer Orientation: Teeth should bite into both the fastener head and the mating surface
Multiple Washers: Avoid stacking multiple washers unless necessary; use a single washer of proper thickness instead
Countersunk Applications: Always use a flat washer under the head when using countersunk screws in soft materials
Clean Surfaces: Ensure washer seating surfaces are clean and free of debris for proper load distribution
Applications
Construction & Architecture: Structural steel connections, handrail mounting, curtain wall systems
Marine & Offshore: Boat building, dock hardware, offshore platform installations
Industrial Machinery: Equipment assembly, conveyor systems, machine mounting
Automotive & Transportation: Vehicle assembly, trailer manufacturing, rail components
Renewable Energy: Solar panel mounting, wind turbine assembly, hydroelectric equipment
Electrical & Electronics: Grounding connections, panel mounting, equipment racks
Furniture Manufacturing: Assembly fittings, hardware installation
Plumbing & HVAC: Pipe hangers, equipment supports, ductwork suspension
