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M21x75mm Carbon Steel Hex Head Cap Screw

Expert Overview

This M21x75mm hex head cap screw, crafted from high-grade carbon steel, offers superior strength and durability for heavy-duty industrial applications. Its robust design ensures reliable fastening in critical assemblies.

StandardASTM A106
MaterialCarbon Steel
FinishGalvanized
GradeN/A
SizeM21
Length75mm
Head Width30mm

Detailed Engineering Specifications

Designed for demanding industrial environments, this M21x75mm hex head cap screw features a nominal diameter of M21 and a length of 75mm. The head width measures 30mm, providing ample surface area for torque application. Manufactured from premium carbon steel, it exhibits excellent tensile strength and shear strength, making it ideal for high-stress joints. Its hardened properties resist deformation under significant load, ensuring structural integrity in machinery, construction, and heavy equipment.

🧊 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 the mating threads are clean and free of debris. 2. Thread the cap screw into the designated component by hand to prevent cross-threading. 3. Tighten the cap screw using an appropriately sized wrench or socket to the specified torque value.

Equivalent Standards (Cross-Reference)

Standard SystemDesignation
ISO EquivalentISO 898-1 / ISO 4014
DIN EquivalentDIN 931 / DIN 933
Primary StandardASTM A106

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 a wrench that is too large or too small for the hex head.Always use a correctly sized socket or wrench to ensure proper engagement and prevent cam-out or damage to the head.
Applying excessive torque, leading to thread stripping or screw fracture.Consult engineering drawings or torque charts for the recommended torque specification and use a calibrated torque wrench.

Common Applications

  • Heavy Machinery Assembly
  • Structural Steel Connections
  • Automotive Manufacturing

⚠️ Engineering Warnings

  • Ensure proper thread engagement to avoid stripping or fastener failure.
  • Wear appropriate personal protective equipment (PPE) during handling and 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 = 75mmAF30mm1/2"-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.