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M21x72mm 304 Stainless Steel Hex Cap Screw

Expert Overview

This M21x72mm hex head cap screw is forged from high-grade 304 stainless steel, offering exceptional corrosion resistance and tensile strength. Engineered for reliable, long-lasting connections in challenging environments.

StandardDIN 933
Material304 Stainless Steel
FinishPlain
GradeN/A
SizeM21
Length72mm
Head Width27mm

Detailed Engineering Specifications

Precision-manufactured to tight tolerances, this M21x72mm hex head cap screw is constructed from premium 304 stainless steel, renowned for its superior corrosion resistance, including against a wide range of chemicals and saltwater. The material's inherent toughness ensures high tensile strength, making it ideal for applications requiring robust and secure fastening under significant load. Its standard hex head design, with a nominal width of 27mm, allows for efficient torque application using standard tools. This screw is engineered for durability and performance in demanding industrial, marine, and construction settings where material integrity 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. Ensure the mating threads are clean and free of debris. 2. Hand-thread the cap screw to confirm alignment and prevent cross-threading. 3. Using an appropriate wrench or socket, tighten the screw to the recommended torque specification for the application, ensuring a secure and stable connection.

Equivalent Standards (Cross-Reference)

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

Mechanical Properties

Tensile Strength75,000 psi (515 MPa)
Yield Strength30,000 psi (205 MPa)
Elongation in 2 in.40% min
HardnessRockwell B95 max

Chemical Composition

Carbon (C)0.08% max
Chromium (Cr)18.0 - 20.0%
Nickel (Ni)8.0 - 10.5%
Manganese (Mn)2.00% max

Temperature & Environment Rating

Min Operating Temp
-320°F (-195°C)
Max Continuous Temp
1400°F (760°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 / SaltwaterGood
Chemical / AcidicNot Recommended

Common Mistakes & How to Avoid Them

❌ Mistake✅ Correct Approach
Using the wrong size wrench, leading to stripped head or improper torque.Always use the correct size wrench or socket that fits snugly on the hex head.
Over-tightening the screw, which can lead to thread damage or material fatigue.Adhere to manufacturer-recommended torque values for the specific application and material.
Not verifying thread compatibility between the screw and the mating component.Confirm that both the screw and the receiving thread are of the same size, pitch, and thread form (e.g., metric M21).

Common Applications

  • Marine hardware and equipment
  • Chemical processing equipment
  • Outdoor structural assemblies
  • Food processing machinery

⚠️ Engineering Warnings

  • Ensure proper personal protective equipment (PPE) is worn during installation.
  • Do not use in applications where the material's temperature limits may be exceeded.

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, 304 Stainless Steel made from?

A: This Hex Head Cap Screw, 304 Stainless Steel is manufactured from 304 Stainless Steel.

Q: What are the main applications?

A: Marine hardware and equipment, Chemical processing equipment, Outdoor structural assemblies, Food processing machinery.

Technical Schematic

HEX BOLT DIAGRAMSAE J429 / ASME B18.2.1HEXHEADLENGTH = 72mmAF27mm1/2"-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.