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M21x82mm 304 Stainless Steel Hex Cap Screw

Expert Overview

Engineered for demanding environments, this M21x82mm hex head cap screw, forged from high-grade 304 stainless steel, ensures exceptional strength and corrosion resistance. Its 20mm head width provides optimal torque application.

StandardASME B18
Material304 Stainless Steel
FinishBlack Oxide
GradeN/A
SizeM21
Length82mm
Head Width20mm

Detailed Engineering Specifications

A proven choice for industrial professionals, this M21x82mm hex head cap screw boasts a robust 304 stainless steel construction, renowned for its excellent tensile strength and superior resistance to oxidation and corrosion across a wide temperature range. The M21 designation signifies its metric thread size, while the 82mm length provides substantial engagement for secure fastening. The 20mm hex head width is engineered for compatibility with standard industrial tools, facilitating efficient installation and reliable torque application. This fastener is ideal for applications requiring long-term durability in harsh or corrosive atmospheres, such as marine, chemical processing, and outdoor structural assemblies.

🧊 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. Insert the cap screw through the components to be joined. 3. Tighten the cap screw using an appropriate wrench or socket to the recommended torque specification, ensuring a secure and stable connection.

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
Overtightening the screw, leading to thread stripping or component damage.Utilize a torque wrench and adhere to the recommended torque specifications for the material and application.
Using the wrong size wrench, which can round off the hex head and prevent proper tightening.Always use a correctly sized wrench or socket that fits snugly on the hex head.

Common Applications

  • Structural steel connections
  • Machinery and equipment assembly
  • Marine and offshore installations

⚠️ Engineering Warnings

  • Ensure compatibility with mating components and thread types.
  • Always wear appropriate personal protective equipment (PPE) during 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, 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, Machinery and equipment assembly, Marine and offshore installations.

Technical Schematic

HEX BOLT DIAGRAMSAE J429 / ASME B18.2.1HEXHEADLENGTH = 82mmAF20mm1/2"-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.