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M8 x 139mm 304 Stainless Steel Hex Cap Screw

Expert Overview

Engineered for superior performance, this M8 x 139mm hex cap screw is crafted from premium 304 stainless steel. It offers exceptional corrosion resistance and strength for critical fastening applications.

StandardDIN 933
Material304 Stainless Steel
FinishAnodized
GradeN/A
SizeM8
Length139mm
Head Width8mm

Detailed Engineering Specifications

Built to exacting engineering tolerances, this M8 x 139mm hex head cap screw features a nominal diameter of 8mm and a length of 139mm. The robust 304 stainless steel composition provides excellent tensile strength and resistance to a wide range of corrosive environments, including saltwater and many chemicals, making it suitable for marine, food processing, and chemical plant applications. The hex head design ensures a secure grip for high-torque applications when used with appropriate tooling. This fastener meets stringent industrial standards for reliability and durability.

🧊 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 mating threads are clean and free of debris. 2. Apply appropriate lubricant if high torque is required or galling is a concern. 3. Securely tighten the hex head cap screw using a calibrated torque wrench to the manufacturer's recommended specification.

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 incorrect thread pitch for the application.Verify the thread pitch of the cap screw matches the tapped hole or nut precisely to prevent cross-threading and ensure secure engagement.
Over-tightening the fastener, leading to thread stripping or material fatigue.Utilize a torque wrench set to the specified torque value for the fastener size and material to avoid over-stressing the threads and components.

Common Applications

  • Marine and offshore equipment assembly
  • Food processing machinery
  • Chemical plant infrastructure
  • Outdoor structural components

⚠️ Engineering Warnings

  • Ensure proper torque is applied to prevent over-tightening or under-tightening.
  • For high-stress applications, consider thread locking compounds if vibration is a factor.

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: Marine and offshore equipment assembly, Food processing machinery, Chemical plant infrastructure, Outdoor structural components.

Technical Schematic

HEX BOLT DIAGRAMSAE J429 / ASME B18.2.1HEXHEADLENGTH = 139mmAF8mm1/2"-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.