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M21 x 59mm Aluminum 6061 Hex Head Cap Screw | Fastening

Expert Overview

This M21 x 59mm Hex Head Cap Screw, crafted from Aluminum 6061, offers superior corrosion resistance and excellent strength-to-weight ratio. Engineered for reliable, lightweight fastening solutions.

StandardASME B18
MaterialAluminum 6061
FinishBlack Oxide
GradeN/A
SizeM21
Length59mm
Head Width8mm

Detailed Engineering Specifications

Built to exacting engineering tolerances, this M21 x 59mm Hex Head Cap Screw is manufactured from Aerospace Grade Aluminum 6061-T6. This alloy provides a remarkable combination of strength, ductility, and corrosion resistance, making it ideal for applications where weight reduction is critical without compromising structural integrity. The precise M21 thread pitch and 59mm length, coupled with a nominal head width of 8mm, ensure secure and consistent engagement in demanding environments, from automotive and aerospace assemblies to marine hardware and custom fabrication projects requiring non-magnetic properties.

🧊 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 mating threads are clean and free of debris. 2. Thread the cap screw by hand to verify alignment and prevent cross-threading. 3. Tighten to the specified torque using an appropriate hex driver, avoiding over-tightening to prevent thread stripping or material deformation.

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
Using excessive force leading to stripped threads.Always adhere to the recommended torque specifications for Aluminum 6061 fasteners and use calibrated torque wrenches.
Not verifying compatibility of mating materials.Ensure the mating component is designed to accommodate the thread pitch and material properties of Aluminum 6061 to prevent galvanic corrosion or premature failure.

Common Applications

  • Aerospace structural components
  • Automotive lightweighting
  • Marine hardware and fittings
  • Custom fabrication and prototyping

⚠️ Engineering Warnings

  • Aluminum 6061 has lower tensile strength than steel; do not use in applications requiring extreme load-bearing capacity without proper engineering analysis.
  • Avoid use in environments with highly corrosive chemicals or prolonged exposure to saltwater without appropriate protective coatings or sealants.

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 lightweighting, Marine hardware and fittings, Custom fabrication and prototyping.

Technical Schematic

HEX BOLT DIAGRAMSAE J429 / ASME B18.2.1HEXHEADLENGTH = 59mmAF8mm1/2"-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.