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M21x50mm Aluminum 6061 Hex Cap Screw

Expert Overview

This M21x50mm hex cap screw, crafted from robust Aluminum 6061, offers exceptional strength-to-weight ratio and superior corrosion resistance. Featuring a 34mm head width, it ensures secure and reliable fastening for a wide range of demanding applications.

StandardASME B18
MaterialAluminum 6061
FinishZinc Plated
GradeN/A
SizeM21
Length50mm
Head Width34mm

Detailed Engineering Specifications

Engineered for reliability and performance, this M21x50mm hex head cap screw is manufactured from high-strength Aluminum 6061-T6 alloy, renowned for its excellent corrosion resistance, weldability, and moderate mechanical properties. The M21 thread provides substantial load-bearing capacity, while the 50mm length accommodates various joint thicknesses. The 34mm hex head allows for secure torque application using standard tooling, preventing stripping and ensuring a tight, stable connection. Ideal for environments where weight reduction and resistance to oxidation are critical, such as 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. Clean both the threaded hole and the screw threads to remove any debris or contaminants. 2. Apply a suitable lubricant or anti-seize compound to the threads if recommended for the application to prevent galling. 3. Insert the screw into the designated hole and thread it by hand for the first few turns to ensure proper alignment. 4. Using an appropriate wrench or socket, tighten the hex head to the recommended torque specification for the M21 thread size and the Aluminum 6061 material, avoiding over-tightening.

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 / ExposedExcellent
Marine / SaltwaterNot Recommended
Chemical / AcidicNot Recommended

Common Mistakes & How to Avoid Them

❌ Mistake✅ Correct Approach
Over-tightening aluminum fastenersAlways adhere to the manufacturer's recommended torque specifications. Over-tightening can strip the threads or damage the material, compromising joint integrity.
Not using anti-seize with aluminumWhen joining aluminum to other metals, especially dissimilar ones, use an appropriate anti-seize compound to prevent galvanic corrosion and galling, which can seize the fastener.
Using incorrect toolingEnsure the wrench or socket used fits the 34mm hex head precisely to avoid rounding the corners and to apply torque effectively and safely.

Common Applications

  • Lightweight structural assemblies in aerospace and automotive
  • Corrosion-resistant fixtures in marine environments
  • High-performance bicycle components
  • General purpose fastening requiring good strength and low weight

⚠️ Engineering Warnings

  • Aluminum 6061 has lower tensile strength than steel; do not use in applications requiring extremely high load-bearing capacity without proper engineering analysis.
  • Galvanic corrosion can occur when aluminum is in contact with dissimilar metals in the presence of an electrolyte. Use isolation methods or coatings if necessary.
  • Avoid using this fastener in extremely high-temperature environments where its mechanical properties may degrade.

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: Lightweight structural assemblies in aerospace and automotive, Corrosion-resistant fixtures in marine environments, High-performance bicycle components, General purpose fastening requiring good strength and low weight.

Technical Schematic

HEX BOLT DIAGRAMSAE J429 / ASME B18.2.1HEXHEADLENGTH = 50mmAF34mm1/2"-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.