Hex Bolt Black

Product Introduction

• Standard Name: Black Oxide Hex Bolt (Blackened Hex Head Bolt).

• Common Names: Blackened Bolt, Black Hex Head Screw.

• Product Definition: A bolt featuring a hexagonal head with a black oxide finish (oxidized surface treatment). This treatment provides basic rust prevention, a deep matte black appearance, and reduces light reflection. It remains a classic choice for applications prioritizing visual consistency, glare reduction, and short-term rust protection.

Hex Bolt Black Key Features

• Black Oxide Finish: Provides basic rust and wear protection with a matte black finish, reducing light

  reflection and improving lubricity, suitable for moderately corrosive environments.

• Hexagonal Head Design: Facilitates torque application using wrenches or socket tools, ensuring efficient

  installation and removal.

• Material and Strength: Commonly used alloy steel or carbon steel, strength grades such as 8.8 or 10.9,

  capable of withstanding moderate loads; conforms to standards such as DIN 931 and ISO 4014.

• Various Specifications: Diameters M6-M36, lengths 20mm-300mm, supports full or partial threads.

• Advantages: Economical and practical, aesthetically pleasing and understated, but the coating is

  relatively thin, making it unsuitable for high-humidity environments.

Working Principle

• Thread Matching: The external thread mates with the nut or internal thread of the hole, generating axial

  force through rotation, forming a clamping force.

• 2. Load Transfer: When torque is applied, the bolt tensile stress is distributed; the black oxide layer

  reduces friction and improves efficiency.

• 3. Protection Mechanism: Black oxide forms a phosphate layer, providing mild corrosion protection

  and lubrication; the principle involves mechanical friction and surface chemical reaction.

• 4. Installation Control: Use a torque wrench to avoid overtightening and damaging the coating;

  combined with washers, stability is enhanced.

Product Applications

• Machinery Manufacturing: Secure equipment components, machine tools, or conveyor systems; the

  black coating reduces glare and improves safety.

• Automotive Industry: Connect chassis or engine mounts; vibration resistant and provides a discreet

  appearance.

• Construction Engineering: Used for securing interior steel structures or furniture; economical for

  non-extreme environments.

• Electronics & DIY: Assemble appliance housings or home projects; aesthetically pleasing and concealed.

• Industrial Equipment: Used as a standard fastener in production lines or warehouses, balancing cost

  and performance.