Home > Fastening & Joining > Hex Head Cap Screw, 304 Stainless Steel

M21x41mm 304 Stainless Steel Hex Head Cap Screw

Expert Overview

Engineered for superior performance, this M21x41mm hex head cap screw is manufactured from high-grade 304 stainless steel. It offers exceptional corrosion resistance and robust mechanical strength, ideal for critical structural applications.

StandardASME B18
Material304 Stainless Steel
FinishPlain
GradeN/A
SizeM21
Length41mm
Head Width17mm

Detailed Engineering Specifications

Built to exacting engineering tolerances, this M21x41mm hex head cap screw features a 17mm head width for secure torque application. Composed of 304 stainless steel, it provides excellent resistance to rust and corrosion in harsh environments, making it suitable for marine, chemical processing, and outdoor infrastructure projects. Its robust design ensures reliable load-bearing capacity and long-term structural integrity under stress.

🧊 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 size (17mm). 2. Ensure the mating threads are clean and free of debris. 3. Thread the cap screw into the designated receiving component, applying gradual and even torque until the specified tightness is achieved.

Equivalent Standards (Cross-Reference)

Standard SystemDesignation
ISO EquivalentISO 898-1 / ISO 4014
DIN EquivalentDIN 931 / DIN 933
Primary StandardASME B18

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-tightening the screw, leading to thread stripping or component damage.Use a calibrated torque wrench and adhere to recommended torque specifications for the material and application.
Using the wrong size socket, which can round off the hex head and impede proper tightening.Always verify that the socket size precisely matches the hex head width (17mm in this case).

Common Applications

  • Structural framing in corrosive environments
  • Marine and offshore equipment assembly
  • Chemical processing plant maintenance

⚠️ Engineering Warnings

  • Ensure compatibility with mating threads and materials to prevent galvanic corrosion.
  • Always wear appropriate safety glasses during installation and operation.

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 framing in corrosive environments, Marine and offshore equipment assembly, Chemical processing plant maintenance.

Technical Schematic

HEX BOLT DIAGRAMSAE J429 / ASME B18.2.1HEXHEADLENGTH = 41mmAF17mm1/2"-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.