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M21x69mm Aluminum 6061 Hex Cap Screw | Fastening

Expert Overview

Engineered for demanding applications, this M21 x 69mm Hex Cap Screw features superior corrosion resistance and a lightweight profile, leveraging the strength of Aluminum 6061.

StandardASME B18
MaterialAluminum 6061
FinishPlain
GradeN/A
SizeM21
Length69mm
Head Width21mm

Detailed Engineering Specifications

Manufactured under strict quality controls, this M21 x 69mm Hex Head Cap Screw is precisely machined from premium Aluminum 6061 alloy. This material offers an excellent balance of strength, lightness, and exceptional corrosion resistance, making it ideal for environments prone to oxidation. The M21 nominal diameter and 69mm nominal length, coupled with a 21mm head width, ensure robust and secure fastening in a wide range of structural and mechanical assemblies. Its low density minimizes overall component weight, a critical factor in aerospace, automotive, and marine industries.

🧊 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 from debris. 2. Hand-thread the screw to confirm proper engagement and alignment. 3. Torque the screw to the manufacturer's recommended specification using a calibrated torque wrench, ensuring the head is seated flush against the mating surface.

Equivalent Standards (Cross-Reference)

Standard SystemDesignation
ISO EquivalentISO 898-1 / ISO 4014
DIN EquivalentDIN 931 / DIN 933
Primary StandardASME B18

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 / ExposedModerate
Marine / SaltwaterNot Recommended
Chemical / AcidicNot Recommended

Common Mistakes & How to Avoid Them

❌ Mistake✅ Correct Approach
Over-torquing the aluminum screw.Always use a calibrated torque wrench and adhere to the specified torque values for Aluminum 6061 fasteners to prevent thread stripping or material deformation.
Using dissimilar metals in corrosive environments without proper isolation.When joining Aluminum 6061 to other metals, consider using dielectric grease or isolating washers to prevent galvanic corrosion.

Common Applications

  • Aerospace structural components
  • Automotive chassis and body assembly
  • Marine hardware and fittings
  • Lightweight industrial machinery

⚠️ Engineering Warnings

  • Aluminum 6061 has lower tensile strength compared to steel; select fasteners appropriate for the load requirements.
  • Avoid use in applications requiring high-temperature resistance or extreme wear resistance without further consideration.

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, Automotive chassis and body assembly, Marine hardware and fittings, Lightweight industrial machinery.

Technical Schematic

HEX BOLT DIAGRAMSAE J429 / ASME B18.2.1HEXHEADLENGTH = 69mmAF21mm1/2"-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.