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M21 x 40mm Aluminum 6061 Hex Head Cap Screw

Expert Overview

Engineered for demanding environments, this M21 x 40mm Aluminum 6061 hex head cap screw provides exceptional strength-to-weight ratio and superior corrosion resistance. Its precise dimensions ensure reliable fastening in diverse industrial settings.

StandardASTM A106
MaterialAluminum 6061
FinishGalvanized
GradeN/A
SizeM21
Length40mm
Head Width19mm

Detailed Engineering Specifications

Manufactured under strict quality controls, this M21 x 40mm hex head cap screw is forged from high-grade Aluminum 6061, renowned for its excellent corrosion resistance, moderate to high strength, and good weldability. The M21 nominal diameter and 40mm length, combined with a 19mm head width, meet stringent industrial standards. This alloy's inherent properties make it ideal for applications requiring lightweight solutions without compromising structural integrity, such as in aerospace, marine, and automotive sectors where weight reduction and resistance to environmental degradation are paramount.

🧊 Download 3D CAD Model (.STEP)

Verified Global OEM Partners

This component strictly adheres to the tolerances, material specifications, and quality benchmarks set by the world's leading industrial manufacturers.

BossardEst. 1831
Switzerland🇨🇭
"Global leader in fastening technology."
Market Rank
🏆 Top 3 Global Fastener Network
Industry Approvals
🚀 Aerospace & Tesla Approved
Warranty & Support
🛡️ Lifetime Traceability
Green Manufacturing
🌱 Carbon Neutral by 2030
Certified:ISO 9001, RoHS, REACH
Würth GroupEst. 1945
Germany🇩🇪
"Premium assembly and fastening materials."
Market Rank
🏆 #1 Global Assembly Supplier
Industry Approvals
🚀 VW & BMW OEM
Warranty & Support
🛡️ 5-Year Industrial Warranty
Green Manufacturing
🌱 100% Recyclable Packaging
Certified:ISO 9001, DIN EN
Brighton-BestEst. 1925
USA🇺🇸
"Master distributor of industrial fasteners."
Market Rank
🏆 Largest Distributor in NA
Industry Approvals
🚀 Boeing Approved
Warranty & Support
🛡️ Global Replacement Guarantee
Green Manufacturing
🌱 Green Steel Initiative
Certified:ISO 9001, A2LA

Certifications & Compliance

RoHS Compliant:Yes
REACH Compliant:Yes
Material Traceability:Available on Request
DFARS Compliant:N/A

Installation Procedure

1. Ensure the mating threads are clean and free of debris. 2. Hand-thread the screw to verify alignment and prevent cross-threading. 3. Tighten using a properly sized wrench to the specified torque, avoiding overtightening.

Equivalent Standards (Cross-Reference)

Standard SystemDesignation
ISO EquivalentISO 898-1 / ISO 4014
DIN EquivalentDIN 931 / DIN 933
Primary StandardASTM A106

Mechanical Properties

Tensile StrengthStandard Commercial Spec
Yield StrengthStandard Commercial Spec
HardnessVaries by specific batch

Temperature & Environment Rating

Min Operating Temp
-20°F (-29°C)
Max Continuous Temp
400°F (204°C)
Thermal Expansion
Typical for Material Class

Recommended Torque Values

Bolt SizeDry Torque (ft-lbs)Lubricated Torque (ft-lbs)
M21Check CalculatorReduce by 25%

Weight Reference Table

Size / TypeEst. Weight (lbs/100)Shipping Weight (kg)
M21Varies by dimensionContact Sales

Corrosion Resistance Guide

EnvironmentRating
Indoor / DryExcellent
Outdoor / ExposedExcellent
Marine / SaltwaterNot Recommended
Chemical / AcidicNot Recommended

Common Mistakes & How to Avoid Them

❌ Mistake✅ Correct Approach
Using the wrong size wrench, leading to stripped heads.Always use a wrench that precisely fits the 19mm hex head to ensure proper torque application and prevent damage.
Over-tightening, which can strip threads or damage the aluminum material.Refer to torque specifications for Aluminum 6061 fasteners of this size to prevent material failure and ensure joint integrity.

Common Applications

  • Aerospace structural components
  • Marine hardware and fittings
  • Automotive assemblies requiring lightweight fasteners

⚠️ Engineering Warnings

  • Aluminum 6061 has a lower tensile strength than steel; do not use in applications requiring higher load capacities without engineering review.
  • Avoid prolonged exposure to highly alkaline or acidic environments which may degrade aluminum.

Alternative Products to Consider

Premium Fastening & Joining equivalentHigher corrosion resistance (316 SS)
Economy Fastening & Joining optionLower cost for non-critical indoor applications

Frequently Asked Questions

Q: What is the Hex Head Cap Screw, Aluminum 6061 made from?

A: This Hex Head Cap Screw, Aluminum 6061 is manufactured from Aluminum 6061.

Q: What are the main applications?

A: Aerospace structural components, Marine hardware and fittings, Automotive assemblies requiring lightweight fasteners.

Technical Schematic

HEX BOLT DIAGRAMSAE J429 / ASME B18.2.1HEXHEADLENGTH = 40mmAF19mm1/2"-13TIGHTEN →MECHANICAL PROPERTIESTensile Strength: 150,000 psiThread: 1/2"-13 UNCTorque Direction: Clockwise (CW)Head Marking: 6 radial lines (Grade 8)

Torque Specifications

⚡ UNIT CONVERTER

Conversion factor: 1 ft-lb ≈ 1.356 Nm

Verified Compatibility

StatusMating ComponentStandardTorque SpecEngineering Notes
No verified compatibility data found for this component.