Famous Nylon Washer Company & Products

Metal split spring washers rely on sharp edges digging into the mating surfaces, which can damage protective coatings and accelerate corrosion. Nylon washers function via viscoelastic deformation. When compressed under bolt torque, the polyamide material conforms intimately to microscopic surface asperities of both the fastener head and substrate. This elastic rebound maintains a sustained preload tension on the bolt threads while exhibiting a high loss factor (tan δ) that dampens mechanical vibrations and harmonic resonance, preventing backward pitch rotation of the screw threads under cyclic operating stresses.

Because unreinforced polyamides have a lower compressive yield strength than structural steel, clamping torque must be calibrated. For unreinforced PA66 flat washers, compressive surface stress should generally not exceed 35 to 45 MPa at 23°C to eliminate permanent cold flow (creep). For high-torque applications where steel bolts (Grade 8.8 or higher) are utilized, our engineers specify 30% glass-fiber reinforced PA66 (PA66-GF30) or cast MC nylon, which withstand compressive pressures exceeding 120 MPa. Using wide-flange washers (such as DIN 9021 large outer-diameter profiles) also spreads total fastener tension across three times the surface area.

Yes, provided hydraulic pressures remain below 2.5 to 3.0 MPa depending on temperature and flange geometry. Nylon has sufficient cold flow to seal against oil, fuels, coolants, and compressed air. However, for pulsating hydraulic lines exceeding 10 MPa, we recommend using our nylon washers as backup anti-extrusion rings paired with elastomer O-rings, or upgrading to composite polyurethane / POM sealing discs manufactured to customized dimensional tolerances.

Polyamides absorb atmospheric water through hydrogen bonding with the amide groups. At 50% relative humidity, PA6 expands approximately 0.25% to 0.35% linearly, while PA66 expands roughly 0.20%. In fully saturated underwater immersion, linear swelling can reach 1.5% to 2.0%. During tool design, SHUNDA calculates these hygroscopic expansion factors to ensure that washer inner bores do not bind on bolt shanks and outer diameters do not bind in counterbores. In applications requiring extreme dimensional stability regardless of moisture, POM (acetal copolymer) or UHMWPE washers are recommended alternatives.

For standard DIN 125, DIN 9021, and ISO 7089 nylon washers, we maintain ready stock with zero MOQ for off-the-shelf dispatch. For custom-machined CNC washers or specialized shoulder bushings requiring custom lathe tooling, typical sample turnaround is 3 to 5 business days, with production runs delivered in 10 to 14 days. For progressive stamped parts requiring dedicated punch tooling, die fabrication takes 7 to 10 days, followed by continuous production runs up to 1,000,000 units weekly.