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M18 x 69mm 304 Stainless Steel Hex Cap Screws

Expert Overview

This M18 x 69mm hex head cap screw, crafted from premium 304 stainless steel, provides robust and corrosion-resistant fastening for critical industrial assemblies, ensuring long-term structural integrity.

StandardASME B18
Material304 Stainless Steel
FinishBlack Oxide
GradeN/A
SizeM18
Length69mm
Head Width34mm

Detailed Engineering Specifications

Engineered for reliability and performance, this M18 x 69mm hex head cap screw features a nominal diameter of 18mm and a thread pitch suitable for robust engagement. The 304 stainless steel composition offers excellent resistance to a wide range of corrosive environments, including atmospheric, food, and industrial chemicals, due to its chromium and nickel content. The substantial head width of 34mm ensures optimal torque transfer and load distribution, making it ideal for high-stress applications where vibration and environmental exposure are significant concerns. Its precise manufacturing tolerances guarantee consistent fit and function.

🧊 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 mating thread or tapped hole with the correct thread pitch (M18). 2. Apply a suitable lubricant or anti-seize compound to the threads if the application environment warrants it. 3. Insert the cap screw and engage the threads by hand to prevent cross-threading. 4. Use a calibrated torque wrench to tighten the cap screw to the specified torque value for the application, ensuring the 34mm hex head is securely engaged by the wrench.

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)
M18Check CalculatorReduce by 25%

Weight Reference Table

Size / TypeEst. Weight (lbs/100)Shipping Weight (kg)
M18Varies 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 or thread pitch wrench, leading to stripped heads or improper seating.Always use a wrench that precisely fits the 34mm hex head and is appropriate for M18 threads.
Over-torquing the screw, which can lead to thread damage or fastener failure.Refer to engineering specifications or torque charts for the correct tightening torque for M18 screws in the specific material being joined.
Not cleaning the threads of both the screw and the mating hole, potentially causing galling or reduced clamping force.Ensure both the screw threads and the mating hole are clean and free of debris or old threadlocker before installation.

Common Applications

  • Structural steel connections
  • Marine and offshore equipment
  • Food processing machinery
  • Chemical processing equipment
  • Automotive components

⚠️ Engineering Warnings

  • Ensure the mating material is compatible with 304 stainless steel to prevent galvanic corrosion.
  • Always use appropriate personal protective equipment (PPE) when handling and installing fasteners.
  • Verify that the selected length (69mm) is sufficient for the intended joint and provides adequate thread engagement.

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, Marine and offshore equipment, Food processing machinery, Chemical processing equipment, Automotive components.

Technical Schematic

HEX BOLT DIAGRAMSAE J429 / ASME B18.2.1HEXHEADLENGTH = 69mmAF34mm1/2"-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.