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M4 x 21mm Brass Hex Head Cap Screw | High Strength Fastener

Expert Overview

Engineered for superior performance, this M4 x 21mm brass hex head cap screw provides robust fastening with excellent corrosion resistance. Its precise dimensions ensure reliable assembly in a variety of applications.

StandardASME B18
MaterialBrass
FinishGalvanized
GradeN/A
SizeM4
Length21mm
Head Width20mm

Detailed Engineering Specifications

Built to exacting engineering tolerances, this M4 x 21mm brass hex head cap screw offers exceptional dimensional stability and consistent performance. Crafted from high-grade brass, it exhibits superior corrosion resistance, non-magnetic properties, and excellent electrical conductivity, making it ideal for environments where rust and interference are critical concerns. The M4 thread size ensures compatibility with standard metric components, while the 21mm length provides ample engagement for secure joining. The broad 20mm head width distributes load effectively and allows for easy torque application with standard hex tools.

🧊 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. Select the appropriate hex wrench for the M4 screw head. 2. Align the screw with the pre-tapped hole or nut. 3. Gradually tighten the screw, applying consistent torque to secure the components without over-stressing the material. 4. Ensure the desired clamping force is achieved without stripping threads or damaging the workpiece.

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

Chemical Composition

Copper (Cu)60.0 - 63.0%
Zinc (Zn)Balance
Lead (Pb)2.5 - 3.7%

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)
M4Check CalculatorReduce by 25%

Weight Reference Table

Size / TypeEst. Weight (lbs/100)Shipping Weight (kg)
M4Varies 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 hex wrench, leading to cam-out and potential damage to the screw head or tool.Always use a correctly sized hex wrench that fits snugly into the screw head recess.
Over-tightening the brass screw, which can strip the threads or weaken the surrounding material.Tighten the screw to the recommended torque specification for the application, avoiding excessive force.

Common Applications

  • Electrical connectors and busbars
  • Marine hardware and fittings
  • Artistic and decorative metalwork

⚠️ Engineering Warnings

  • Brass is a relatively soft metal; avoid using excessive force during installation.
  • While brass offers good corrosion resistance, it may tarnish over time, especially in certain atmospheric conditions.

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, Brass made from?

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

Q: What are the main applications?

A: Electrical connectors and busbars, Marine hardware and fittings, Artistic and decorative metalwork.

Technical Schematic

HEX BOLT DIAGRAMSAE J429 / ASME B18.2.1HEXHEADLENGTH = 21mmAF20mm1/2"-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.