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M21 x 144mm 304 Stainless Steel Hex Head Cap Screw

Expert Overview

Engineered for robust performance, this M21 x 144mm hex head cap screw is manufactured from premium 304 stainless steel. It offers superior corrosion resistance and high tensile strength, ensuring secure fastening in demanding environments.

StandardDIN 933
Material304 Stainless Steel
FinishGalvanized
GradeN/A
SizeM21
Length144mm
Head Width30mm

Detailed Engineering Specifications

Purpose-built for heavy-duty applications, this M21 x 144mm hex head cap screw features a nominal diameter of M21, a length of 144mm, and a head width of 30mm. Constructed from 304 stainless steel, it provides excellent resistance to corrosion, rust, and pitting, making it ideal for environments exposed to moisture, chemicals, or saltwater. Its robust design ensures high tensile and shear strength, suitable for structural connections, machinery assembly, and critical infrastructure projects where reliability is paramount. The hex head allows for high torque application with standard hex wrenches or sockets, facilitating secure and lasting joins.

🧊 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. Apply appropriate lubrication if required by the application to prevent galling, especially in stainless steel. 3. Insert the cap screw and engage the threads by hand before applying torque with a calibrated 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 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
Over-torquing, leading to thread stripping or fastener fatigue.Utilize a torque wrench and adhere to recommended torque specifications for the material and thread size.
Using incompatible materials for mating components, potentially causing galvanic corrosion with stainless steel.Pair 304 stainless steel fasteners with compatible materials like other stainless steels, or materials with similar electrochemical potential. Consult corrosion charts if unsure.

Common Applications

  • Structural steel connections
  • Heavy machinery and equipment assembly
  • Marine and offshore applications
  • Chemical processing equipment
  • Bridge and infrastructure construction

⚠️ Engineering Warnings

  • Ensure proper thread engagement to avoid cross-threading and premature failure.
  • Always use appropriate personal protective equipment (PPE) during installation, including safety glasses and gloves.

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: Structural steel connections, Heavy machinery and equipment assembly, Marine and offshore applications, Chemical processing equipment, Bridge and infrastructure construction.

Technical Schematic

HEX BOLT DIAGRAMSAE J429 / ASME B18.2.1HEXHEADLENGTH = 144mmAF30mm1/2"-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.