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M21x56mm Hex Head Cap Screw, Carbon Steel

Expert Overview

This M21x56mm Hex Head Cap Screw, crafted from high-strength carbon steel, provides superior torque transfer and durability for critical industrial assemblies and structural connections.

StandardISO 9001
MaterialCarbon Steel
FinishPassivated
GradeN/A
SizeM21
Length56mm
Head Width24mm

Detailed Engineering Specifications

Built to exacting engineering tolerances, this M21x56mm hex head cap screw features a nominal diameter of M21, a grip length of 56mm, and a hex head with a nominal width of 24mm across flats. Manufactured from premium carbon steel, it offers excellent tensile strength and shear resistance, making it suitable for high-load applications where reliability and structural integrity are paramount. The robust design ensures secure mating with standard M21 threaded holes and facilitates efficient torque application via a socket wrench or hex key.

🧊 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:Yes

Installation Procedure

1. Ensure mating threads are clean and free from debris. 2. Engage the screw into the threaded hole, hand-tightening initially to confirm alignment. 3. Apply appropriate torque using a calibrated wrench to the specified tightening torque for the application, ensuring even tightening if multiple fasteners are used.

Equivalent Standards (Cross-Reference)

Standard SystemDesignation
ISO EquivalentISO 898-1 / ISO 4014
DIN EquivalentDIN 931 / DIN 933
Primary StandardISO 9001

Mechanical Properties

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

Chemical Composition

Carbon (C)0.28 - 0.55%
Manganese (Mn)0.60 - 0.90%
Phosphorus (P)0.04% max
Sulfur (S)0.05% max

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 the wrong size wrench or tool, leading to stripped hex head.Always use a wrench or socket that precisely matches the 24mm hex head width to ensure proper engagement and prevent damage.
Over-tightening, causing thread damage or fastener failure.Adhere to recommended torque specifications for the specific material and application to avoid compromising the screw's integrity.

Common Applications

  • Heavy machinery assembly
  • Structural steel connections
  • Automotive and aerospace sub-assemblies

⚠️ Engineering Warnings

  • Ensure proper thread engagement to prevent cross-threading and fastener failure.
  • Always use appropriate safety equipment, including eye protection, during installation.

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, Carbon Steel made from?

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

Q: What are the main applications?

A: Heavy machinery assembly, Structural steel connections, Automotive and aerospace sub-assemblies.

Technical Schematic

HEX BOLT DIAGRAMSAE J429 / ASME B18.2.1HEXHEADLENGTH = 56mmAF24mm1/2"-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.