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M8x139mm 304 Stainless Hex Cap Screw

Expert Overview

This M8x139mm hex head cap screw, crafted from premium 304 stainless steel, offers superior corrosion resistance and high tensile strength. Engineered for robust performance in challenging environments, it ensures reliable and long-lasting fastening solutions.

StandardDIN 933
Material304 Stainless Steel
FinishBlack Oxide
GradeN/A
SizeM8
Length139mm
Head Width15mm

Detailed Engineering Specifications

Purpose-built for heavy-duty applications, this M8x139mm hex head cap screw features a nominal diameter of M8, a total length of 139mm, and a head width of 15mm. Constructed from 304 stainless steel, it exhibits excellent resistance to corrosion, oxidation, and a wide range of chemicals, making it ideal for environments prone to moisture, salt, or acidic exposure. The material's inherent toughness and high tensile strength ensure it can withstand significant loads and vibrations without failure, suitable for demanding industrial machinery, structural assemblies, marine hardware, and outdoor construction projects.

🧊 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. 2. Hand-thread the cap screw to engage the initial threads to prevent cross-threading. 3. Tighten using a properly sized wrench or socket, applying torque gradually according to application requirements and safety standards.

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)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)
M8Check CalculatorReduce by 25%

Weight Reference Table

Size / TypeEst. Weight (lbs/100)Shipping Weight (kg)
M8Varies 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 or socket that precisely matches the 15mm head width to ensure proper engagement and prevent damage.
Cross-threading due to improper initial engagement.Start by hand-threading the screw to confirm it's engaging the mating threads correctly before applying any tools.

Common Applications

  • Industrial Machinery Assembly
  • Marine Hardware and Structures
  • Outdoor Construction and Fabrication

⚠️ Engineering Warnings

  • Ensure compatibility of mating materials to prevent galvanic corrosion if dissimilar metals are used.
  • Do not overtighten, as this can damage the threads or the screw itself.

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: Industrial Machinery Assembly, Marine Hardware and Structures, Outdoor Construction and Fabrication.

Technical Schematic

HEX BOLT DIAGRAMSAE J429 / ASME B18.2.1HEXHEADLENGTH = 139mmAF15mm1/2"-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.