Hex Key  — Product Introduction

Hex key (GB/T 5356-2021) is a common hand tool used for installing and removing hex socket screws and bolts. The current national standard GB/T 5356-2021 provides clear regulations on product type, dimensions, materials, heat treatment hardness, minimum torque, surface quality, test methods, and inspection rules. The product is commonly available in an L-shaped design, available in flat-end and ball-end styles, using metric specifications to match standard hex socket screws, featuring unified dimensions, reliable strength, and excellent interchangeability.

I. Product Features

Standardized and compliant
Manufactured and inspected according to GB/T 5356-2021, with dimensional tolerances, lengths, and chamfers meeting national standard requirements.

Rational structural design
Common L-shaped long-arm/short-arm design: the long arm end provides greater torque output, while the short arm end is suitable for quick turning or operation in confined spaces; ball-end type allows angled tightening.

High-quality materials
Typically made from premium alloy steel or tool steel, subjected to quenching and tempering for an optimal balance of hardness and toughness.

Surface protection
Surfaces may undergo bluing, chromium plating, phosphatizing, or other treatments to enhance rust resistance and wear resistance.

Complete specifications
Covers common metric hex socket sizes: 1.5mm, 2mm, 2.5mm, 3mm, 4mm, 5mm, 6mm, 8mm, 10mm, 12mm, 14mm, 17mm, 19mm, 22mm, 24mm, 27mm, 32mm, 36mm, and more.

II. Product Advantages

Compliant and reliable
Conforms to GB/T 5356-2021 national standard with stable quality, standardized inspection, and guaranteed safety in use.

High fitting precision
Strict control of hex socket size tolerance ensures tight fit with hex socket screw recesses, minimizing slippage and damage to screw recesses.

High strength and long service life
Hardness and torque performance meet standard requirements; resistant to bending, breaking, or chipping, ensuring a long service life.

Labor-saving and efficient operation
Long arm end provides high torque, short arm end offers flexibility, ball-end allows angled operation — all improving assembly and maintenance efficiency.

Strong versatility
Compatible with metric hex socket screws; excellent interchangeability, suitable for standardized operations across multiple industries.

III. Applicable Scope

Suitable for the installation and removal of hex socket screws and bolts in various applications, including:

Machinery equipment assembly, commissioning, and maintenance

Automobile, motorcycle, and bicycle repair

Electronics, instruments, and precision machinery

Furniture, office equipment, and sports equipment

Building hardware and decoration

Aerospace, rail transit, shipbuilding, mold making, and general hardware maintenance