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M21 x 66mm 316 Stainless Steel Hex Head Cap Screw

Expert Overview

Engineered for demanding environments, this M21 x 66mm hex head cap screw is manufactured from premium 316 stainless steel, offering superior corrosion and chemical resistance for critical structural connections.

StandardDIN 933
Material316 Stainless Steel
FinishPassivated
GradeN/A
SizeM21
Length66mm
Head Width22mm

Detailed Engineering Specifications

Trusted by engineers across multiple sectors, this M21 x 66mm hex head cap screw is precision-machined from high-grade 316 stainless steel, renowned for its exceptional resistance to pitting and crevice corrosion, particularly in chloride-rich environments. With a nominal diameter of M21 and a length of 66mm, the fastener features a robust hex head with a 22mm width, ensuring secure torque application. Its inherent non-magnetic properties and excellent strength make it the preferred choice for applications in marine, chemical processing, food and beverage, and pharmaceutical industries where hygiene and material integrity are 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. Clean mating surfaces and threads of both the screw and the receiving component to remove any debris or contaminants. 2. Hand-thread the screw to ensure proper engagement and prevent cross-threading. 3. Using a properly calibrated torque wrench and an appropriate socket, tighten the hex head cap screw to the manufacturer's specified torque value for the application, ensuring even pressure distribution.

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)16.0 - 18.0%
Nickel (Ni)10.0 - 14.0%
Molybdenum (Mo)2.0 - 3.0%

Temperature & Environment Rating

Min Operating Temp
-320°F (-195°C)
Max Continuous Temp
1500°F (815°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 / SaltwaterExcellent
Chemical / AcidicGood

Common Mistakes & How to Avoid Them

❌ Mistake✅ Correct Approach
Overtightening the fastener, leading to thread stripping or material deformation.Always adhere to the recommended torque specifications for the specific application and material being joined. Utilize a calibrated torque wrench.
Using a standard carbon steel screw in a corrosive environment, resulting in premature failure due to rust and degradation.Select fasteners made from materials specifically suited to the environmental conditions. 316 stainless steel is essential for marine, chemical, and high-moisture applications.

Common Applications

  • Marine hardware and vessel construction
  • Chemical processing equipment and piping
  • Food and beverage processing machinery
  • Pharmaceutical manufacturing equipment
  • Structural components in corrosive environments

⚠️ Engineering Warnings

  • Ensure the chosen torque value is appropriate for the materials being fastened to prevent damage.
  • For critical load-bearing applications, consult structural engineering guidelines and material compatibility charts.

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, 316 Stainless Steel made from?

A: This Hex Head Cap Screw, 316 Stainless Steel is manufactured from 316 Stainless Steel.

Q: What are the main applications?

A: Marine hardware and vessel construction, Chemical processing equipment and piping, Food and beverage processing machinery, Pharmaceutical manufacturing equipment, Structural components in corrosive environments.

Technical Schematic

HEX BOLT DIAGRAMSAE J429 / ASME B18.2.1HEXHEADLENGTH = 66mmAF22mm1/2"-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.