Function, Specifications, Materials, and Key Parameters of
81.45501.0077 Wheel Bolt
1. Function
The 81.45501.0077 wheel bolt is a critical fastener used in
automotive wheel assemblies, primarily in heavy-duty commercial
vehicles such as those manufactured by Shaanxi Automobile Group
(e.g., Delong series). Its main functions include:
• Securing the Wheel: It fastens the wheel to the hub, ensuring
that the wheel remains firmly attached during vehicle operation.
• Transmitting Torque: It transfers torque from the axle to the
wheel, enabling the vehicle to move.
• Withstanding Loads: It bears the vehicle's weight and dynamic
loads during driving, including braking and cornering forces.
2. Specifications
• Part Number: 81.45501.0077
• Application: Specifically designed for heavy-duty trucks, such as
Shaanxi Automobile's Delong series (e.g., M3000, X3000).
• Type: Wheel bolt with nut (may include washer in some
configurations).
• Thread Type: Typically a metric thread (e.g., M22 or similar,
depending on the exact specification).
• Thread Pitch: Varies based on design (e.g., 2.0 mm, 2.5 mm,
etc.).
• Length: The overall length of the bolt, which must match the hub
and wheel assembly requirements (e.g., 220 mm in some cases).
• Head Type: Hexagonal head for wrench/socket engagement.
3. Materials
• Bolt Material: Typically made from high-strength alloy steel
(e.g., 40Cr, 42CrMo, or similar) to withstand high tensile and
shear loads.
• Nut Material: Often made from the same or similar alloy steel for
consistency and strength.
• Surface Treatment: May include zinc plating,Dacromet coating, or
other corrosion-resistant finishes to protect against environmental
factors.
4. Key Parameters
• Tensile Strength: The bolt must meet specific tensile strength
requirements (e.g., Grade 10.9 or higher in the metric system).
• Yield Strength: The stress at which the bolt begins to deform
plastically.
• Thread Engagement Length: The minimum length of thread that must
engage with the nut or hub to ensure secure fastening.
• Torque Specification: The recommended torque value for tightening
the bolt to ensure proper clamping force without over-tightening.
• Thread Fit: The class of fit between the bolt and nut (e.g.,
6g/6H for metric threads).
• Head Dimensions: The width across flats (WAF) and height of the
hexagonal head for tool compatibility.
5. English Terminology
• Wheel Bolt: Also referred to as a wheel stud or hub bolt in some
contexts.
• Hexagonal Head: A six-sided head designed for engagement with a
wrench or socket.
• Tensile Strength: The maximum stress a material can withstand
while being stretched or pulled before breaking.
• Yield Strength: The stress at which a material begins to deform
plastically.
• Thread Pitch: The distance between adjacent threads, measured in
millimeters (for metric threads).
• Torque Specification: The recommended rotational force applied to
tighten the bolt.
