Find HS Code and trade information for tightening torque

Tightening Torque

Tightening torque refers to the rotational force applied to a fastener, such as a bolt or screw, to create a desired clamping force. It is a critical parameter in mechanical engineering and assembly, ensuring joints are securely fastened without being over- or under-tightened.

Material Considerations

The materials involved significantly impact the appropriate tightening torque.

• Fastener Material: Steel alloys (e.g., carbon steel, alloy steel, stainless steel) are common. Higher strength steels generally require higher torque values for the same clamping force.
• Joined Material(s): The properties of the materials being joined (e.g., aluminum, plastic, wood) affect friction and the ability to withstand clamping force. Softer materials require lower torque to prevent damage or stripping.
• Coating/Lubrication: Coatings (e.g., zinc, phosphate) and lubricants (e.g., oil, grease) alter friction between the fastener and the joined surfaces, directly influencing the torque-clamping force relationship.

Purpose

• Secure Assembly: Prevents loosening of joints due to vibration, shock, or dynamic loads.
• Load Distribution: Ensures even distribution of forces across the joint, maximizing its strength and preventing stress concentrations.
• Sealing: In some applications, proper tightening torque creates a leak-proof seal.
• Prevent Damage: Avoids stripping threads, deforming components, or causing premature failure.

Function

Tightening torque functions based on the following principle:

• Torque-Clamping Force Relationship: Torque applied to a fastener is converted into a clamping force that holds the joined parts together. This relationship is described by the following equation:

  • T = K * D * P

    Where: * T = Tightening Torque * K = Torque Coefficient (accounts for friction, lubrication, surface finish) * D = Nominal Diameter of the Fastener * P = Desired Clamping Force

• Friction: Friction plays a significant role in this conversion. Higher friction requires more torque to achieve the same clamping force.

• Stretch: Fasteners are designed to stretch slightly under load. This stretch creates the clamping force.

Usage Scenarios

• Automotive Industry: Engine assembly, chassis construction, wheel mounting.
• Aerospace: Aircraft structures, engine components, landing gear.
• Construction: Structural steel connections, bridge assembly.
• Manufacturing: Assembly of machinery, equipment, and appliances.
• Electronics: Securing circuit boards and components.

Common Types of Torque Measurement & Application

• Torque Wrenches: Manual, hydraulic, pneumatic, and electronic wrenches used to apply a specific torque value.
• Torque Screwdrivers: Used for smaller fasteners, often with adjustable torque settings.
• Torque Multipliers: Increase torque output for high-torque applications.
• Torque Control Systems: Automated systems that precisely control torque during assembly.
• Torque-Angle Measurement: Applying a specific torque and a specific angle of rotation to achieve precise clamping force.
• Ultrasonic Screw Fastening: Utilizing ultrasonic vibrations to achieve consistent and accurate tightening.

It is essential to consult manufacturer's specifications for the correct tightening torque values for specific fasteners and applications. Improper torque can lead to joint failure, safety hazards, and reduced performance.

The declared goods, “tightening torque,” relate to the measurement of force applied when fastening. Based on the provided reference material, the following HS codes are relevant:

• 8467290040: This HS code covers “Tools for working in the hand, pneumatic, hydraulic or with self-contained electric or nonelectric motor, and parts thereof: With self-contained electric or nonelectric motor: Other Screwdrivers, nut-runners and impact wrenches”. This code applies if the tightening torque is measured using a powered screwdriver, nut-runner, or impact wrench. Chapter 84 relates to nuclear reactors, boilers, machinery and mechanical appliances; parts thereof. Heading 67 specifically covers tools for working in the hand, pneumatic, hydraulic or with self-contained electric or nonelectric motor. Subheading 29 covers other tools with self-contained electric or nonelectric motor. The total tax rate is 37.5%.

• 9031808060: This HS code covers “Measuring or checking instruments, appliances and machines, not specified or included elsewhere in this chapter; profile projectors; parts and accessories thereof: Other instruments, appliances and machines: Other Equipment for testing the characteristics of internal combustion engines: For testing electrical characteristics”. If the tightening torque measurement is part of a system testing the electrical characteristics of internal combustion engines, this code may apply. Chapter 90 relates to optical, photographic, cinematographic, measuring, checking, precision, medical or surgical instruments and apparatus; parts and accessories thereof. Heading 31 covers measuring or checking instruments, appliances and machines. Subheading 80 covers other instruments, appliances and machines. The total tax rate is 30.0%.

• 9031808070: This HS code covers “Measuring or checking instruments, appliances and machines, not specified or included elsewhere in this chapter; profile projectors; parts and accessories thereof: Other instruments, appliances and machines: Other Equipment for testing the characteristics of internal combustion engines: Other”. If the tightening torque measurement is part of a system testing other characteristics of internal combustion engines, this code may apply. Chapter 90 relates to optical, photographic, cinematographic, measuring, checking, precision, medical or surgical instruments and apparatus; parts and accessories thereof. Heading 31 covers measuring or checking instruments, appliances and machines. Subheading 80 covers other instruments, appliances and machines. The total tax rate is 30.0%.

• 9026806000: This HS code covers “Instruments and apparatus for measuring or checking the flow, level, pressure or other variables of liquids or gases (for example, flow meters, level gauges, manometers, heat meters), excluding instruments and apparatus of heading 9014, 9015, 9028 or 9032; parts and accessories thereof: Other instruments and apparatus: Other: Other”. If the tightening torque is measured as a pressure or force variable, this code may apply. Chapter 90 relates to optical, photographic, cinematographic, measuring, checking, precision, medical or surgical instruments and apparatus; parts and accessories thereof. Heading 26 covers instruments and apparatus for measuring or checking. Subheading 80 covers other instruments and apparatus. The total tax rate is 37.5%.

• 9026906000: This HS code covers “Instruments and apparatus for measuring or checking the flow, level, pressure or other variables of liquids or gases (for example, flow meters, level gauges, manometers, heat meters), excluding instruments and apparatus of heading 9014, 9015, 9028 or 9032; parts and accessories thereof: Parts and accessories: Other: Other”. If the tightening torque measurement involves parts or accessories for measuring pressure or force variables, this code may apply. Chapter 90 relates to optical, photographic, cinematographic, measuring, checking, precision, medical or surgical instruments and apparatus; parts and accessories thereof. Heading 26 covers instruments and apparatus for measuring or checking. Subheading 90 covers parts and accessories. The total tax rate is 55.0%.