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

M21 x 92mm 304 Stainless Steel Hex Cap Screw

Expert Overview

This M21 x 92mm hex head cap screw, forged from premium 304 stainless steel, delivers superior tensile strength and corrosion resistance. Its robust design ensures secure fastening in critical applications.

StandardASME B18
Material304 Stainless Steel
FinishAnodized
GradeN/A
SizeM21
Length92mm
Head Width17mm

Detailed Engineering Specifications

Engineered for reliability and performance, this M21 x 92mm hex head cap screw boasts a nominal diameter of M21, a precise length of 92mm, and a head width of 17mm. Constructed from 304 stainless steel, it offers excellent corrosion resistance, making it ideal for environments exposed to moisture, chemicals, or marine conditions. The 304 alloy provides a balance of strength and ductility, ensuring long-term integrity under significant load. Its hex head design facilitates high torque application with standard wrenches, crucial for securing heavy machinery, structural components, and critical assemblies where vibration resistance and durability 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. Ensure the mating threads are clean and free from debris or damage. 2. Apply a suitable lubricant or anti-seize compound if required by the application. 3. Insert the screw and thread it by hand for at least two full turns to prevent cross-threading. 4. Tighten the screw using an appropriate torque wrench to the specified torque value for the mating component and the screw's grade.

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
Using the wrong size wrench, leading to head stripping.Always use a wrench that properly fits the 17mm hex head to avoid damage and ensure accurate torque application.
Over-torquing the screw, causing thread damage or material fatigue.Utilize a calibrated torque wrench and adhere to recommended torque specifications for the fastener and the assembly.
Cross-threading the screw during installation.Start threading by hand for several turns to confirm proper alignment before using a tool.

Common Applications

  • Heavy machinery assembly
  • Structural steel connections
  • Marine and offshore equipment
  • Chemical processing plants
  • Food and beverage processing equipment

⚠️ Engineering Warnings

  • Ensure compatibility of mating materials to prevent galvanic corrosion when used with dissimilar metals.
  • Do not exceed the maximum recommended torque for this fastener; consult engineering specifications for your specific application.

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: Heavy machinery assembly, Structural steel connections, Marine and offshore equipment, Chemical processing plants, Food and beverage processing equipment.

Technical Schematic

HEX BOLT DIAGRAMSAE J429 / ASME B18.2.1HEXHEADLENGTH = 92mmAF17mm1/2"-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.