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M21x123mm Carbon Steel Hex Head Cap Screw

Expert Overview

This M21x123mm Hex Head Cap Screw, crafted from robust carbon steel, is engineered for superior strength and durability in critical industrial applications. Its precise dimensions ensure secure and reliable fastening.

StandardDIN 933
MaterialCarbon Steel
FinishZinc Plated
GradeN/A
SizeM21
Length123mm
Head Width21mm

Detailed Engineering Specifications

A high-performance industrial component, this M21x123mm Hex Head Cap Screw is manufactured from high-grade carbon steel, offering excellent tensile strength and resistance to shear forces, making it ideal for heavy-duty applications. The M21 thread size ensures compatibility with standard M21 nuts and tapped holes, while the 123mm length provides ample grip for joining thicker components. The 21mm hex head facilitates high torque application with standard tooling, enabling secure and reliable connections in demanding environments. Its material properties make it suitable for use in construction, machinery, and structural assemblies where load-bearing capacity is paramount.

🧊 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. Select the appropriate torque wrench and socket for the M21 hex head. 2. Ensure the mating threaded hole or nut is clean and free of debris. 3. Thread the cap screw into the assembly by hand to prevent cross-threading, then tighten to the specified torque value using the torque wrench.

Equivalent Standards (Cross-Reference)

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

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 / ExposedExcellent
Marine / SaltwaterNot Recommended
Chemical / AcidicNot Recommended

Common Mistakes & How to Avoid Them

❌ Mistake✅ Correct Approach
Using an impact wrench which can over-torque and damage the threads or component.Always use a calibrated torque wrench to achieve the correct tightening specification.
Not cleaning the mating threads, leading to galling or reduced clamping force.Thoroughly inspect and clean both the screw threads and the mating threads before assembly.

Common Applications

  • Heavy machinery assembly
  • Structural steel connections
  • Automotive manufacturing

⚠️ Engineering Warnings

  • Ensure the correct torque is applied to avoid over-tightening or under-tightening.
  • Always use appropriate personal protective equipment (PPE) 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 manufacturing.

Technical Schematic

HEX BOLT DIAGRAMSAE J429 / ASME B18.2.1HEXHEADLENGTH = 123mmAF21mm1/2"-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.