Carriage bolt DIN603

Definition and Basic Structure

Definition: Galvanized screw is a transmission component that is coated with a zinc layer (electroplated zinc or hot-dip zinc) on the surface of the screw. It is mainly used to convert rotational motion into linear motion and has anti-corrosion ability.

Core structure:

Base material: usually carbon steel (such as 45 # steel, 40Cr) or stainless steel, with a zinc layer covering the surface after galvanizing.

Thread type: commonly trapezoidal thread (Tr type) or ball screw, the latter is mostly used in high-precision scenarios.

Galvanizing process: divided into electroplated zinc (thin and uniform coating) and hot-dip zinc (thick coating, strong corrosion resistance).

Characteristics of galvanizing process

Corrosion prevention mechanism:

Sacrificial anode protection: The zinc layer preferentially oxidizes, delaying the corrosion of the substrate steel.

Physical barrier: A dense zinc layer isolates water vapor, oxygen, and substrate from contact.

Process comparison:

Process type Coating thickness Corrosion resistance Applicable scenarios Cost

Galvanized 5-20 μ m for general indoor equipment, with low corrosion environment

Hot dip galvanizing 50-150 μ m, excellent in outdoor, chemical, and marine environments

Core advantages

Corrosion resistance: Suitable for humid, salt spray, acidic and alkaline environments (such as ships and chemical equipment).

Economy: The cost of galvanizing is lower than that of stainless steel lead screws, and the lifespan is significantly extended.

Low maintenance: The self-healing properties of the zinc layer reduce the need for frequent maintenance.

Adaptability: Can be matched with various transmission systems, such as stepper motors and servo motors.

Application scenarios

Outdoor machinery: construction machinery, agricultural equipment (exposed to rainwater and soil environments).

Ship and ocean engineering: deck lifting mechanism, valve control (resistant to salt spray corrosion).

Chemical equipment: reaction kettle transmission system, pipeline regulating device (acid and alkali resistant medium).

Construction industry: automatic doors and windows, lifting platforms (low-cost rust prevention requirements).

Food processing: meets hygiene standards (requires smooth surface and no risk of rust).