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M21 x 145mm 316 Stainless Steel Hex Head Cap Screw

Expert Overview

Engineered for superior performance in corrosive settings, this M21 x 145mm Hex Head Cap Screw offers robust fastening with its 316 stainless steel construction. Ideal for critical industrial applications.

StandardASTM A106
Material316 Stainless Steel
FinishZinc Plated
GradeN/A
SizeM21
Length145mm
Head Width27mm

Detailed Engineering Specifications

Designed for demanding industrial environments, this M21 x 145mm Hex Head Cap Screw is manufactured from premium 316 stainless steel, renowned for its exceptional corrosion and pitting resistance, even in marine and chemical-laden atmospheres. The M21 nominal diameter, coupled with a 145mm length and a 27mm hex head width, provides substantial clamping force and ease of torque application with standard tooling. Its high tensile strength and durability ensure reliable performance under significant mechanical stress and extreme temperatures, making it suitable for structural assemblies, machinery, and outdoor infrastructure where longevity and integrity are paramount.

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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. Hand-thread the cap screw to verify alignment and prevent cross-threading. 3. Tighten the cap screw to the specified torque using a calibrated torque wrench, ensuring even pressure distribution.

Equivalent Standards (Cross-Reference)

Standard SystemDesignation
ISO EquivalentISO 898-1 / ISO 4014
DIN EquivalentDIN 931 / DIN 933
Primary StandardASTM A106

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)16.0 - 18.0%
Nickel (Ni)10.0 - 14.0%
Molybdenum (Mo)2.0 - 3.0%

Temperature & Environment Rating

Min Operating Temp
-320°F (-195°C)
Max Continuous Temp
1500°F (815°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 / SaltwaterExcellent
Chemical / AcidicGood

Common Mistakes & How to Avoid Them

❌ Mistake✅ Correct Approach
Using the wrong size wrench, leading to head stripping.Always use a correctly sized hex socket or wrench to match the 27mm head width.
Over-torquing the fastener, potentially damaging the threads or the workpiece.Consult the relevant engineering specifications for the correct torque value and utilize a calibrated torque wrench.
Using standard carbon steel fasteners in corrosive environments.Always select 316 stainless steel for applications exposed to saltwater, chemicals, or high humidity to prevent premature corrosion and failure.

Common Applications

  • Marine and offshore equipment
  • Chemical processing plants
  • Food and beverage manufacturing
  • Structural steel assemblies
  • Heavy machinery and equipment

⚠️ Engineering Warnings

  • Ensure proper thread engagement to avoid cross-threading.
  • Do not exceed the maximum recommended torque specification for this fastener.
  • Always use appropriate safety equipment, including eye protection, when working with fasteners.

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, 316 Stainless Steel made from?

A: This Hex Head Cap Screw, 316 Stainless Steel is manufactured from 316 Stainless Steel.

Q: What are the main applications?

A: Marine and offshore equipment, Chemical processing plants, Food and beverage manufacturing, Structural steel assemblies, Heavy machinery and equipment.

Technical Schematic

HEX BOLT DIAGRAMSAE J429 / ASME B18.2.1HEXHEADLENGTH = 145mmAF27mm1/2"-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.