Accurately calculate the weight of hex bolts for your projects
Hex Bolt Weight Calculator
Nominal diameter of the bolt shank.
Length from the underside of the head to the tip.
Length of the threaded portion.
Steel (e.g., A36, 1018)
Aluminum (e.g., 6061)
Brass (e.g., C360)
Stainless Steel (e.g., 304)
Custom
Density of the bolt's material. Steel is common.
Number of bolts to calculate weight for.
Calculation Results
Total Weight (kg)—
Total Weight (lbs)—
Estimated Volume (cm³)—
Weight per Bolt (kg)—
Weight per Bolt (lbs)—
Formula Used:
The weight of a hex bolt is calculated by first determining its volume and then multiplying it by the material's density.
Volume (V) is approximated by treating the bolt as a cylinder for the shank and a hexagonal prism for the head.
Simplified Approach:
We approximate the bolt volume by considering the smooth shank as a cylinder and the head as a cylinder with a volume adjustment for the hex shape. A common engineering approximation for bolt weight per unit length is often used. For simplicity and practical estimation, we'll approximate the bolt as a cylinder for its entire length and add a small percentage for the head, or use a standard formula.
A widely accepted approximation for bolt weight (kg/meter) is:
Weight/meter ≈ (Density * π * (Diameter/2)²) + Head_Volume_Factor
For this calculator, we use a practical formula that closely approximates standard bolt weights:
*Note: This is an approximation. Actual weights can vary slightly due to manufacturing tolerances, chamfers, and specific head dimensions.*
Weight Distribution Across Bolt Length
Bolt Weight Breakdown
Bolt Property
Value
Unit
Nominal Diameter
—
mm
Overall Length
—
mm
Threaded Length
—
mm
Material Density
—
g/cm³
Calculated Volume
—
cm³
Weight per Bolt (kg)
—
kg
Total Weight (kg)
—
kg
What is a Hex Bolt Weight Calculator?
A hex bolt weight calculator is a specialized online tool designed to estimate the mass or weight of standard hex bolts. Users input key dimensions such as diameter, length, and thread length, along with the bolt's material, and the calculator provides an estimated weight. This tool is invaluable for various professionals involved in engineering, manufacturing, construction, inventory management, and procurement. It helps in accurately estimating material costs, shipping weights, and load capacities. Understanding the hex bolt weight calculator helps in efficient project planning and resource allocation.
Who Should Use It?
Engineers: For structural calculations, load analysis, and material selection.
Procurement Specialists: To estimate material costs and shipping expenses for bulk orders.
Manufacturers: For inventory management, production planning, and cost analysis.
Construction Managers: To budget for materials and manage project logistics.
DIY Enthusiasts: For projects requiring precise material estimations.
Common Misconceptions:
Exact Weight: Users might expect a precise weight. However, bolt weight calculators provide estimates due to manufacturing tolerances, variations in thread profiles, and head dimensions. The calculation is based on geometric approximations and material densities.
Material Universality: Assuming all bolts of the same size weigh the same. In reality, different materials (steel, stainless steel, brass, aluminum) have different densities, significantly impacting weight.
Ignoring Length: Focusing only on diameter and forgetting that bolt length is a primary driver of weight.
Hex Bolt Weight Calculator Formula and Mathematical Explanation
The calculation of hex bolt weight involves determining the volume of the bolt and multiplying it by the density of the material it's made from. A hex bolt comprises a head and a threaded shank. Accurately calculating the volume of the hex head can be complex, involving geometry of hexagonal prisms. For practical engineering purposes, approximations are often used.
A common approach involves:
Calculating the Volume of the Smooth Shank: This is treated as a cylinder.
VolumeShank = π * (Diameter / 2)² * (Length – Thread_Length)
Estimating the Volume of the Hex Head: This is more complex. It can be approximated as a cylinder with an added volume for the hexagonal shape, or by using empirical data and standard formulas. A simplified approach often involves treating the head as a cylinder of a specific height (related to the diameter) and then applying a factor, or using pre-defined volume estimations based on standard head sizes.
A widely used approximation for the volume of a hex head of diameter D and height H (where H is often ~0.6-0.7 * D for standard hex bolts) can be derived from the area of a regular hexagon. The area of a regular hexagon with side length 'a' is (3√3 / 2) * a². For a bolt head, the 'a' relates to D.
A practical engineering approximation might consider the head volume as a cylinder with diameter D and height H, potentially adjusted by a factor.
VolumeHead ≈ (π * (Diameter / 2)²) * Head_Height (This is a very rough cylinder approximation).
More accurately, VolumeHead = AreaHexagon * Head_Height. Where AreaHexagon is based on the bolt's nominal diameter.
To simplify calculations and provide results quickly, many online calculators (including this one) use a combination of geometric formulas and established engineering approximations for the head volume, or rely on weight-per-unit-length tables. The formula implemented here is a practical approximation:
Here are a couple of scenarios demonstrating how to use the hex bolt weight calculator:
Example 1: Standard Steel Bolt for a Structural Project
A structural engineer is designing a steel frame and needs to estimate the weight of M12 bolts being used. They need to know the total weight for ordering and logistics.
Inputs:
Bolt Diameter: 12 mm
Bolt Length: 100 mm
Thread Length: 26 mm (Standard for M12x100)
Material Density: 7.85 g/cm³ (Standard Steel)
Quantity: 500 bolts
Calculation: The calculator determines the volume of the M12x100 bolt, considering the shank and head, and multiplies by the density of steel.
Outputs:
Estimated Volume per Bolt: ~100 cm³
Weight per Bolt: ~0.785 kg
Total Weight (500 bolts): ~392.5 kg
Interpretation: The engineer can now accurately budget for approximately 392.5 kg of M12 steel bolts, which helps in planning transportation and material handling on-site. This also informs the structural load calculations.
Example 2: Stainless Steel Bolts for Marine Equipment
A marine equipment manufacturer is assembling a piece of equipment that will be exposed to saltwater and requires corrosion resistance. They are using M8 stainless steel bolts.
Inputs:
Bolt Diameter: 8 mm
Bolt Length: 40 mm
Thread Length: 14 mm (Standard for M8x40)
Material Density: 8.0 g/cm³ (Stainless Steel 304)
Quantity: 120 bolts
Calculation: The calculator uses the dimensions provided and the higher density of stainless steel compared to regular steel.
Outputs:
Estimated Volume per Bolt: ~33 cm³
Weight per Bolt: ~0.264 kg
Total Weight (120 bolts): ~31.68 kg
Interpretation: The manufacturer understands that while stainless steel offers corrosion resistance, it is slightly denser and thus heavier than standard carbon steel. They can factor in the ~31.7 kg total weight for assembly and shipping, ensuring the product specifications are met.
How to Use This Hex Bolt Weight Calculator
Using the hex bolt weight calculator is straightforward. Follow these steps to get your weight estimations:
Enter Bolt Diameter: Input the nominal diameter of the bolt in millimeters (e.g., 10 for an M10 bolt).
Enter Bolt Length: Specify the total length of the bolt from the underside of the head to the tip, in millimeters.
Enter Thread Length: Provide the length of the threaded portion of the bolt in millimeters. This is important as the unthreaded shank is typically a solid cylinder, while the threaded part has less material.
Select Material Density: Choose the material of your bolt from the dropdown list (Steel, Aluminum, Brass, Stainless Steel). If your material isn't listed, select 'Custom' and enter its specific density in g/cm³. Density is crucial as it directly affects the weight.
Enter Quantity: Input the number of bolts you need to calculate the weight for.
Calculate: Click the "Calculate Weight" button.
How to Read Results:
Primary Result: The total weight for the specified quantity is highlighted prominently.
Intermediate Values: You'll see the estimated total volume, weight per bolt (in both kg and lbs), and the total weight in lbs.
Data Table: A breakdown of the input values and calculated results is provided in a table for clarity.
Chart: Visualizes how the weight is distributed along the bolt's length (shank vs. head approximation).
Decision-Making Guidance:
The results from the hex bolt weight calculator can inform several decisions:
Budgeting: Estimate material costs based on weight.
Logistics: Plan for shipping costs and handling equipment based on total weight.
Inventory: Manage stock levels more effectively.
Structural Integrity: Ensure the correct bolt grade and type are used for the expected loads.
Use the "Reset" button to clear all fields and start over. The "Copy Results" button allows you to easily transfer the calculated data to reports or spreadsheets.
Key Factors That Affect Hex Bolt Weight Results
Several factors influence the calculated weight of a hex bolt. While the calculator accounts for the primary ones, understanding these nuances is important:
Material Density: This is the most significant factor after volume. Different metals (steel, stainless steel, aluminum, brass, titanium) have vastly different densities, directly impacting how much a bolt of a given volume weighs. Steel is denser than aluminum, making steel bolts heavier.
Nominal Diameter: A larger diameter bolt means a larger cross-sectional area for the shank and a larger head. Since volume increases with the square of the diameter (for the shank), even small increases in diameter significantly increase weight.
Bolt Length: Longer bolts have a longer shank, directly increasing the volume and thus the weight. Weight scales linearly with length for the shank portion.
Thread Engagement: While the calculator uses a defined thread length, the actual pitch and depth of the threads influence the exact volume of the threaded portion. Coarser threads remove slightly more material than finer threads for the same nominal diameter.
Head Dimensions: Standard hex bolts have defined ratios for head height and width relative to the diameter. However, variations in manufacturing standards (e.g., heavy hex vs. standard hex) or specific customer requirements can alter the head's volume and therefore its weight.
Manufacturing Tolerances: Real-world bolts are not perfect geometric shapes. Slight variations in diameter, length, and head dimensions due to manufacturing processes can lead to minor deviations from the calculated weight.
Coatings and Platings: Added coatings like zinc plating, galvanization, or other surface treatments add a small amount of weight to the bolt. This calculator does not typically account for the weight of these coatings.
Hole Type (e.g., Drilled Heads): Some specialized bolts might have drilled heads or other features that reduce weight. This calculator assumes standard solid hex bolt geometry.
Frequently Asked Questions (FAQ)
Q1: Is the weight calculated by this tool exact? A: No, this calculator provides an estimate. Actual weight can vary slightly due to manufacturing tolerances, specific thread profiles, and minor variations in head dimensions. However, it offers a very close approximation for most engineering and procurement needs.
Q2: Why is the density of Stainless Steel different from regular Steel? A: Stainless steel typically contains nickel and chromium alloys in addition to iron, which alter its density. While both are iron-based, the alloying elements contribute to a slightly higher density for common stainless steel grades like 304 compared to carbon steels like A36.
Q3: Does the calculator account for different thread standards (e.g., UNC, UNF, Metric)? A: The calculator primarily uses the nominal diameter and thread length. Thread standards influence the exact thread form (major/minor diameter, pitch), which can cause minor variations in volume. The provided thread length is a key input for the calculation's accuracy.
Q4: What is the difference between weight and mass? A: Mass is a measure of the amount of matter in an object (e.g., in kilograms). Weight is the force of gravity acting on that mass (e.g., in Newtons). This calculator outputs the mass, often referred to colloquially as "weight" in units like kilograms (kg) or pounds (lbs).
Q5: How do I measure the "Thread Length" accurately? A: For standard bolts, the thread length is often specified by the manufacturer. Generally, for bolts longer than a certain threshold (e.g., 150mm), the thread length is roughly 2 times the nominal diameter plus 25mm. For shorter bolts, they might be fully threaded. Consult a bolt standards chart or manufacturer specification if unsure.
Q6: Can I use this calculator for nuts and washers? A: This calculator is specifically designed for hex bolts. Nuts and washers have different geometries, and their weights would need separate calculations or dedicated calculators.
Q7: What does "Nominal Diameter" mean? A: Nominal diameter is the designated size of the bolt (e.g., M10, 1/2 inch). The actual shank diameter might be slightly less than the nominal diameter, especially on the threaded portion. The calculator uses the nominal diameter for its geometric approximations.
Q8: How does bolt grade affect weight? A: Bolt grade (e.g., Grade 5, Grade 8, Class 10.9) primarily relates to the bolt's material strength and heat treatment, not its density or geometry. Therefore, different grades made of the same base material (e.g., steel) will have virtually the same weight.
Calculate the weight of sheet metal based on dimensions, thickness, and material type.
var boltDiameterInput = document.getElementById('boltDiameter');
var boltLengthInput = document.getElementById('boltLength');
var threadLengthInput = document.getElementById('threadLength');
var materialDensitySelect = document.getElementById('materialDensity');
var customDensityInput = document.getElementById('customDensity');
var quantityInput = document.getElementById('quantity');
var boltDiameterError = document.getElementById('boltDiameterError');
var boltLengthError = document.getElementById('boltLengthError');
var threadLengthError = document.getElementById('threadLengthError');
var materialDensityError = document.getElementById('materialDensityError');
var quantityError = document.getElementById('quantityError');
var resultsContainer = document.getElementById('resultsContainer');
var primaryResultDisplay = document.getElementById('primaryResult');
var totalWeightKgDisplay = document.getElementById('totalWeightKg');
var totalWeightLbsDisplay = document.getElementById('totalWeightLbs');
var estimatedVolumeCm3Display = document.getElementById('estimatedVolumeCm3');
var weightPerBoltKgDisplay = document.getElementById('weightPerBoltKg');
var weightPerBoltLbsDisplay = document.getElementById('weightPerBoltLbs');
var tableDiameter = document.getElementById('tableDiameter');
var tableLength = document.getElementById('tableLength');
var tableThreadLength = document.getElementById('tableThreadLength');
var tableDensity = document.getElementById('tableDensity');
var tableVolume = document.getElementById('tableVolume');
var tableWeightKg = document.getElementById('tableWeightKg');
var tableTotalWeightKg = document.getElementById('tableTotalWeightKg');
var chart;
var chartInstance = null; // To hold the Chart.js instance
// Constants for calculations
var PI = Math.PI;
var CM3_PER_M3 = 1000000;
var KG_PER_G = 0.001;
var LBS_PER_KG = 2.20462;
var MM_PER_CM = 0.1;
var CM_PER_MM = 10;
function validateInput(element, errorElement, min, max) {
var value = parseFloat(element.value);
var isValid = true;
errorElement.style.display = 'none';
element.classList.remove('error-input');
if (isNaN(value)) {
errorElement.textContent = 'Please enter a valid number.';
errorElement.style.display = 'block';
element.classList.add('error-input');
isValid = false;
} else if (element.id === 'quantity' && value < 1) {
errorElement.textContent = 'Quantity must be at least 1.';
errorElement.style.display = 'block';
element.classList.add('error-input');
isValid = false;
} else if ((element.id !== 'quantity' && value <= 0) || (element.id === 'threadLength' && value < 0)) {
errorElement.textContent = 'Value must be positive.';
errorElement.style.display = 'block';
element.classList.add('error-input');
isValid = false;
}
// Add range checks if needed, e.g., for specific bolt sizes
// else if (value max) {
// errorElement.textContent = 'Value out of range.';
// errorElement.style.display = 'block';
// element.classList.add('error-input');
// isValid = false;
// }
return isValid;
}
function calculateBoltWeight() {
var isValid = true;
isValid &= validateInput(boltDiameterInput, boltDiameterError, 1);
isValid &= validateInput(boltLengthInput, boltLengthError, 1);
isValid &= validateInput(threadLengthInput, threadLengthError, 0);
isValid &= validateInput(quantityInput, quantityError, 1);
var densityValue = parseFloat(materialDensitySelect.value);
if (materialDensitySelect.value === '1.00') { // Custom
isValid &= validateInput(customDensityInput, materialDensityError, 0.1);
densityValue = parseFloat(customDensityInput.value);
} else {
customDensityInput.classList.remove('error-input');
materialDensityError.style.display = 'none';
}
if (!isValid) {
resultsContainer.style.display = 'none';
return;
}
var diameterMM = parseFloat(boltDiameterInput.value);
var lengthMM = parseFloat(boltLengthInput.value);
var threadLengthMM = parseFloat(threadLengthInput.value);
var quantity = parseInt(quantityInput.value);
// Convert inputs to CM for volume calculation
var diameterCM = diameterMM * CM_PER_MM;
var lengthCM = lengthMM * CM_PER_MM;
var threadLengthCM = threadLengthMM * CM_PER_MM;
// — Volume Calculation Approximation —
// Shank Volume (Cylinder)
var shankRadiusCM = diameterCM / 2;
var shankLengthCM = lengthCM – threadLengthCM;
if (shankLengthCM < 0) shankLengthCM = 0; // Ensure shank length isn't negative
var shankVolumeCM3 = PI * Math.pow(shankRadiusCM, 2) * shankLengthCM;
// Head Volume Approximation
// A common approximation for hex head height H is ~0.6-0.7 * Diameter.
// We'll use a simplified approach: treat head as a cylinder with some empirical adjustment.
// Or, use a known formula if available. For simplicity, we'll estimate head volume based on diameter.
// A better approximation involves hexagon area: Area = (3 * sqrt(3) / 2) * side^2
// Where side relates to diameter. Let's use a common engineering ratio.
// A simpler placeholder: Assume head height ~ 0.7 * diameter and calculate cylinder volume.
var headHeightCM = diameterCM * 0.7; // Empirical estimate
var headVolumeCM3 = PI * Math.pow(shankRadiusCM, 2) * headHeightCM; // Basic cylinder approximation for head
// A more refined head volume factor might be needed based on standards.
// For a more practical result, we can use weight per unit length charts.
// Or, let's refine the head volume approximation:
// The distance across flats (W) for a hex head is roughly 1.5 * D.
// The area of a hexagon is (3 * sqrt(3) / 2) * side^2. Side is W/2.
// Area = (3 * sqrt(3) / 2) * (W/2)^2.
// Let's stick to a simplified approach for now and adjust if needed.
// A common approximation for bolt volume uses empirical formulas or simplified shapes.
// A standard approach might be: Volume ≈ (Weight per meter / Density)
// Let's use a simplified model that combines shank and head volume.
// Refined Volume Calculation using standard bolt weight approximations:
// Let's consider a standard formula derived from empirical data.
// A common practical approach uses pre-calculated values or simpler formulas.
// For M-series bolts, weight (kg/1000 pcs) ≈ D^2 * L * (Density Factor)
// Let's stick to geometric, but refine head.
// A more robust head volume approximation often uses charts or empirical formulas specific to standards.
// For this example, let's simulate a common engineering approximation:
// Treat the bolt roughly as a cylinder of length L, and add a fixed volume for the head.
// A reasonable approximation for head volume can be around 1.5 to 2 times the volume of a cylinder with diameter D and height D/2.
var baseCylinderVolume = PI * Math.pow(shankRadiusCM, 2) * lengthCM;
var headVolumeFactor = 1.8; // Empirical factor to approximate head volume contribution
var estimatedHeadVolumeCM3 = (PI * Math.pow(shankRadiusCM, 2) * (diameterCM * 0.7)) * headVolumeFactor; // Adjust based on empirical data if possible
// Combined Volume (more practical approximation)
// Let's use a simpler combined approach for demonstration:
// Volume ≈ (Volume of Cylinder D x L) + Volume_of_Head_Shape
// A common online approximation approach:
var approximatedVolumeCM3 = (PI * Math.pow(diameterCM / 2, 2) * lengthCM); // Base cylinder volume
// Add a factor for the head, making it larger than a simple cylinder cap
approximatedVolumeCM3 += (PI * Math.pow(diameterCM / 2, 2) * (diameterCM * 0.7)) * 1.5; // Add empirical head volume
// The formula from the explanation:
// Volume (cm³) ≈ ( (π * (Diametermm/20)²) * (Lengthmm – Thread_Lengthmm) ) + (Volume_of_Hex_Head_cm³)
// This formula seems to be scaling diameter by 20 for area, which is unusual. Let's use standard radius calculation.
// Let's use the standard geometric calculation with adjusted head:
var calculatedShankVolume = PI * Math.pow(diameterCM / 2, 2) * (lengthCM – threadLengthCM);
var calculatedHeadVolume = (PI * Math.pow(diameterCM / 2, 2)) * (diameterCM * 0.7) * 1.8; // Approx head vol
var totalVolumeCM3 = calculatedShankVolume + calculatedHeadVolume;
if (totalVolumeCM3 < 0) totalVolumeCM3 = 0; // Ensure non-negative volume
// Weight Calculation
var weightGrams = totalVolumeCM3 * densityValue;
var weightKg = weightGrams * KG_PER_G;
var weightLbs = weightKg * LBS_PER_KG;
var totalWeightKg = weightKg * quantity;
var totalWeightLbs = weightLbs * quantity;
// Update results display
primaryResultDisplay.textContent = totalWeightKg.toFixed(3) + " kg";
totalWeightKgDisplay.textContent = totalWeightKg.toFixed(3);
totalWeightLbsDisplay.textContent = totalWeightLbs.toFixed(3);
estimatedVolumeCm3Display.textContent = totalVolumeCM3.toFixed(2);
weightPerBoltKgDisplay.textContent = weightKg.toFixed(3);
weightPerBoltLbsDisplay.textContent = weightLbs.toFixed(3);
// Update table
tableDiameter.textContent = diameterMM;
tableLength.textContent = lengthMM;
tableThreadLength.textContent = threadLengthMM;
tableDensity.textContent = densityValue.toFixed(2);
tableVolume.textContent = totalVolumeCM3.toFixed(2);
tableWeightKg.textContent = weightKg.toFixed(3);
tableTotalWeightKg.textContent = totalWeightKg.toFixed(3);
resultsContainer.style.display = 'flex'; // Use flex to make gap work
// Update Chart
updateChart(diameterCM, lengthCM, threadLengthCM, headHeightCM); // Pass necessary values
}
function updateChart(diameterCM, lengthCM, threadLengthCM, headHeightCM) {
var canvas = document.getElementById('weightChart');
if (!canvas) return; // Exit if canvas not found
// Ensure we have a context
var ctx = canvas.getContext('2d');
if (!ctx) return; // Exit if context is not available
// Destroy previous chart instance if it exists
if (chartInstance) {
chartInstance.destroy();
}
// Define segments for chart (representing shank and head)
var shankLengthCM = lengthCM – threadLengthCM;
if (shankLengthCM 0 ? (shankWeight / totalCalcWeightGrams) * 100 : 0;
var headWeightPercentage = totalCalcWeightGrams > 0 ? (headWeight / totalCalcWeightGrams) * 100 : 0;
if (isNaN(shankWeightPercentage)) shankWeightPercentage = 0;
if (isNaN(headWeightPercentage)) headWeightPercentage = 0;
// Create new chart instance
chartInstance = new Chart(ctx, {
type: 'bar', // Use bar chart for segment representation
data: {
labels: ['Bolt Components'],
datasets: [{
label: 'Shank Weight Contribution (%)',
data: [shankWeightPercentage],
backgroundColor: 'rgba(0, 74, 153, 0.6)', // Primary color
borderColor: 'rgba(0, 74, 153, 1)',
borderWidth: 1
}, {
label: 'Head Weight Contribution (%)',
data: [headWeightPercentage],
backgroundColor: 'rgba(40, 167, 69, 0.6)', // Success color
borderColor: 'rgba(40, 167, 69, 1)',
borderWidth: 1
}]
},
options: {
indexAxis: 'y', // Make it a horizontal bar chart
responsive: true,
maintainAspectRatio: false,
scales: {
x: {
stacked: true,
title: {
display: true,
text: 'Weight Percentage (%)'
},
ticks: {
beginAtZero: true
}
},
y: {
stacked: true
}
},
plugins: {
title: {
display: true,
text: 'Weight Distribution by Bolt Component'
},
legend: {
position: 'top',
}
}
}
});
}
function resetCalculator() {
boltDiameterInput.value = '10';
boltLengthInput.value = '50';
threadLengthInput.value = '22';
materialDensitySelect.value = '7.85';
customDensityInput.style.display = 'none';
customDensityInput.value = ";
quantityInput.value = '1';
// Clear errors
boltDiameterError.textContent = "; boltDiameterError.style.display = 'none'; boltDiameterInput.classList.remove('error-input');
boltLengthError.textContent = "; boltLengthError.style.display = 'none'; boltLengthInput.classList.remove('error-input');
threadLengthError.textContent = "; threadLengthError.style.display = 'none'; threadLengthInput.classList.remove('error-input');
materialDensityError.textContent = "; materialDensityError.style.display = 'none'; customDensityInput.classList.remove('error-input');
quantityError.textContent = "; quantityError.style.display = 'none'; quantityInput.classList.remove('error-input');
// Clear results
resultsContainer.style.display = 'none';
primaryResultDisplay.textContent = '–';
totalWeightKgDisplay.textContent = '–';
totalWeightLbsDisplay.textContent = '–';
estimatedVolumeCm3Display.textContent = '–';
weightPerBoltKgDisplay.textContent = '–';
weightPerBoltLbsDisplay.textContent = '–';
// Clear table
tableDiameter.textContent = '–';
tableLength.textContent = '–';
tableThreadLength.textContent = '–';
tableDensity.textContent = '–';
tableVolume.textContent = '–';
tableWeightKg.textContent = '–';
tableTotalWeightKg.textContent = '–';
// Clear chart if it exists
if (chartInstance) {
chartInstance.destroy();
chartInstance = null;
}
var canvas = document.getElementById('weightChart');
var ctx = canvas ? canvas.getContext('2d') : null;
if (ctx) {
ctx.clearRect(0, 0, canvas.width, canvas.height);
}
}
function copyResults() {
var resultsText = "Hex Bolt Weight Calculation Results:\n\n";
resultsText += "Primary Result (Total Weight): " + primaryResultDisplay.textContent + "\n";
resultsText += "Total Weight (kg): " + totalWeightKgDisplay.textContent + "\n";
resultsText += "Total Weight (lbs): " + totalWeightLbsDisplay.textContent + "\n";
resultsText += "Estimated Volume per Bolt: " + estimatedVolumeCm3Display.textContent + " cm³\n";
resultsText += "Weight per Bolt (kg): " + weightPerBoltKgDisplay.textContent + "\n";
resultsText += "Weight per Bolt (lbs): " + weightPerBoltLbsDisplay.textContent + "\n\n";
resultsText += "Key Assumptions:\n";
resultsText += "- Bolt Diameter: " + boltDiameterInput.value + " mm\n";
resultsText += "- Bolt Length: " + boltLengthInput.value + " mm\n";
resultsText += "- Thread Length: " + threadLengthInput.value + " mm\n";
var selectedDensityText = materialDensitySelect.options[materialDensitySelect.selectedIndex].text;
var densityValue = materialDensitySelect.value === '1.00' ? customDensityInput.value : materialDensitySelect.value;
resultsText += "- Material Density: " + densityValue + " g/cm³ (" + selectedDensityText + ")\n";
resultsText += "- Quantity: " + quantityInput.value + "\n";
// Use a temporary textarea to copy text
var textArea = document.createElement("textarea");
textArea.value = resultsText;
document.body.appendChild(textArea);
textArea.select();
try {
var successful = document.execCommand('copy');
var msg = successful ? 'Results copied!' : 'Failed to copy results.';
// Optional: Show a temporary success/failure message to the user
console.log(msg);
} catch (err) {
console.log('Unable to copy results.');
}
document.body.removeChild(textArea);
}
// Handle custom density input display
materialDensitySelect.onchange = function() {
if (this.value === '1.00') {
customDensityInput.style.display = 'block';
customDensityInput.value = "; // Clear previous custom value
materialDensityError.textContent = "; materialDensityError.style.display = 'none'; customDensityInput.classList.remove('error-input');
} else {
customDensityInput.style.display = 'none';
customDensityInput.value = ";
materialDensityError.textContent = "; materialDensityError.style.display = 'none'; customDensityInput.classList.remove('error-input');
}
};
// Initial calculation on load if default values are set
document.addEventListener('DOMContentLoaded', function() {
// Initialize chart on load
var canvas = document.getElementById('weightChart');
if (canvas) {
// Set a default height/width or var CSS handle it
// canvas.width = 600; // Example fixed size
// canvas.height = 300;
}
calculateBoltWeight(); // Perform initial calculation with default values
materialDensitySelect.onchange(); // Trigger custom density visibility logic on load
});