Metering Rod Body Material
The coating rod body is commonly fabricated from stainless steel grades including 304 stainless steel and 303 stainless steel. These materials deliver outstanding corrosion resistance and wear resistance, making them well-suited for use with various coating solutions.
To further boost surface hardness and wear resistance while lowering surface friction, premium coating rods are often treated with hard chrome plating, with the plating thickness typically kept at approximately 25 μm. Additionally, some metering rods are coated with Teflon to effectively prevent particle accumulation and coating streaking during operation.
Surface Structure
The surface structure of a metering rod directly defines its coating performance, and is mainly categorized into two types: smooth coating rods and grooved coating rods.
Smooth metering rods feature a seamless groove-free surface and are primarily applied for hydrodynamic metering. Their outer diameter and surface finish act as critical factors influencing coating application volume.
By contrast, grooved coating rods are engineered with continuous wave-shaped grooves on the surface or wrapped with steel wire, designed specifically for volumetric metering. Groove shape, depth and width directly govern the coating wet film thickness, serving as the core parameters for controlling overall coating precision.