A bolt must be tightened enough to keep the joint compressed under all operating conditions, but not so tight that it breaks during assembly. VDI 2230 helps calculate the maximum and minimum assembly preloads based on the tightening method used (e.g., torque wrench vs. hydraulic tensioner). 3. Embedding and Relaxation (
The guideline is structured for cylindrical bolted joints with standard metric threads (ISO 262), where the bolt strength is at least ISO 8.8 or higher. Part 1 was last revised in February 2015 (the current active version as of this writing), with a new edition expected to incorporate updates from ISO/TC 2 fasteners.
Select an initial trial bolt size, thread pitch, and strength class (e.g., 8.8, 10.9, or 12.9) based on the maximum anticipated operational load. Step 3: Calculate Stiffness Constants Determine the elastic resilience of the bolt ( δBdelta sub cap B ) and the clamped parts ( δPdelta sub cap P vdi 2230 part 1 pdf
) and account for the loss of preload due to "embedding" (the flattening of surface roughness over time).
Ben’s bolt never snapped again. And deep in his hard drive, in a folder marked “Sacred Texts,” sat the crooked, scanned, beautiful ghost of VDI 2230 Part 1. A bolt must be tightened enough to keep
The standard is built around (R0 to R10). Here is an overview of what each step accomplishes:
If the joint experiences cyclic loading, calculate the alternating stress amplitude ( σasigma sub a Select an initial trial bolt size, thread pitch,
Accounts for inaccuracies in tools (e.g., torque wrenches vs. angle-controlled tightening) using the "Tightening Factor" ( αAalpha sub cap A Friction Coefficients (
What (e.g., 8.8, 10.9, 12.9) and bolt size are you currently evaluating?