Generate an ordered tightening sequence for multi-bolt patterns using cross, star, circular and alternating layouts.
Sequence Settings
For critical joints, use the actual manufacturer's or engineering tightening procedure. This planner provides an ordered sequence only; it does not determine tightening torque or required preload.
Ready to generate a tightening sequence.
Tightening Sequence
Generated Bolt Order
—
Bolts
—
total
Passes
—
tightening stages
Pattern
—
method
First Bolt
—
starting point
Last Bolt
—
final position
Ordered Tightening Steps
Step
Pass
Order
Bolt
Action
Bolt Pattern Preview
BOLT PATTERN
Simplified sequence visualization
The diagram is a planning visualization. Bolt positions are distributed around a simplified pattern and are not a fabrication drawing.
Cross / Star Sequence
For a typical even-numbered rectangular or circular pattern, a cross or star sequence moves between opposing or widely separated bolt positions before progressively tightening the remaining bolts.
Example for 8 bolts: 1 → 5 → 3 → 7 → 2 → 6 → 4 → 8
The exact order should be adapted to the actual physical bolt arrangement.
Circular Alternating Sequence
For circular patterns, the planner alternates between positions around the pattern rather than tightening adjacent bolts consecutively.
Example for 8 bolts: 1 → 5 → 2 → 6 → 3 → 7 → 4 → 8
This creates a distributed progression around the flange.
Multiple Tightening Passes
Multiple passes can be useful when a joint requires progressive tightening rather than immediately applying the final target torque.
Pass 1 → Pass 2 → Pass 3 → Final Pass
The planner repeats the generated order for each selected pass. Actual torque percentages for each pass should be specified by the applicable installation procedure.
Important Limitations
This tool generates a preliminary bolt tightening order.
It does not calculate tightening torque.
It does not calculate bolt preload.
It does not verify achieved preload.
It does not account for gasket compression requirements.
It does not analyze flange deformation.
It does not account for eccentric loading or joint-specific stiffness.
Actual tightening sequences may be specified by the equipment or fastener manufacturer.
Critical pressure, structural and safety-related joints require the applicable engineering or installation procedure.
Important: A generated sequence is a planning reference, not a substitute for the specified tightening procedure. For critical joints, follow the manufacturer's instructions, project specifications and applicable engineering requirements.
Frequently Asked Questions
What does the Bolt Tightening Sequence Planner generate?
It generates an ordered list of bolt numbers for common multi-bolt patterns.
Why not simply tighten bolts in numerical order?
Sequential adjacent tightening can concentrate clamping force locally. Distributed patterns such as cross or star sequences are commonly used to progressively distribute tightening across a joint.
Can I use multiple tightening passes?
Yes. The planner can generate up to four passes using the selected sequence.
Does it calculate the torque for each pass?
No. Torque or preload targets must be obtained from the applicable specification or installation procedure.
Can it handle circular bolt patterns?
Yes. Circular alternating sequences can be generated and visualized.
Can I change the starting bolt?
Yes. Enter the desired physical starting bolt number.