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Welding & Machining of Armor Plates – Practical Tips for Fabricators

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Working with armor steel plates like HIND ARMOR 500, HSC 500T, or MIL-DTL-46100 equivalents?
One of the biggest challenges for fabricators and OEMs is:
“How do we properly weld, cut, and machine high hardness armor plates without compromising ballistic performance?”

At Hindustan Steel Corporation, we not only supply armor plates but also guide clients on best practices for welding and machining to avoid cracking, soft spots, or structural weakness.

Understanding the Metallurgy of Armor Plates

Armor steel plates undergo quenching and tempering, giving them:

  • High surface hardness (470–540 BHN for HHA grades)
  • High tensile strength (1400–1800 MPa)
  • Limited ductility compared to mild steel

This metallurgy makes them highly resistant to bullets but also sensitive to heat inputs and fabrication errors.

Challenges in Welding and Machining Armor Steel

  • Risk of heat-affected zone (HAZ) softening
  • Potential for cracking during or after welding
  • Tool wear and tear during drilling/machining
  • Difficulty in cold bending, especially for thick plates

Our team offers guidelines and support to help avoid these issues during on-site fabrication.

Mechanical Properties That Affect Fabrication

Property Range
Hardness 470–540 BHN (HHA Grades)
Tensile Strength 1400–1800 MPa
Elongation 8–12%
Impact Toughness Controlled per heat batch

These properties dictate the choice of cutting, drilling, and welding methods.

Welding Guidelines for Armor Plates

Preheat Temperature (For >10 mm thickness):
120°C to 160°C, depending on plate thickness.

Interpass Temperature:
Maximum 200°C

Recommended Welding Process:
GMAW (MIG/MAG) or SMAW (Stick Welding) with low hydrogen electrodes.

Post-Weld Treatment:
Allow slow cooling, cover with thermal blankets if needed.

Welding Tip:
Minimize heat input to prevent HAZ softening.
Short, controlled weld runs preferred.

Cutting and Drilling Tips for Armor Steel

Process Recommendation
Cutting Waterjet, Plasma, or Laser Cutting (with controlled heat)
Drilling Carbide-tipped tools at low RPM with high feed rate
CNC Profiling Available at Hindustan Steel Corporation

For thickness above 20 mm, waterjet or low-speed plasma is preferred to maintain edge hardness.

Bending & Forming of Armor Plates

  1. Cold bending: Only recommended for thin plates (6 mm to 8 mm max) with large bend radius.
  2. Thicker plates: Prefer multi-part assembly rather than bending.
  3. Improper bending can cause surface cracks or internal micro-fractures.

Heat Affected Zone (HAZ) Control Tips

  • Minimize heat input
  • Use controlled preheat and interpass monitoring
  • Maintain arc stability during welding
  • Back-step welding technique helps distribute heat load
  • Post-weld visual and UT inspection recommended

Fabrication Services Available at Hindustan Steel Corporation

  • Waterjet Cutting
  • CNC Plasma and Laser Cutting
  • CNC Drilling and Profiling
  • Pre-cut Door Panels for Ballistic Applications
  • Welding Advisory Support for OEMs

We help reduce fabrication risk for vehicle armorers, defense contractors, and security project fabricators.

Popular Armor Grades We Help Fabricate

  • HIND ARMOR 500
  • HSC 500T Tactical Armor
  • MIL-DTL-46100 Equivalent Plates
  • STANAG 4569 Level Plates
  • EN 1522 FB6/FB7 Equivalents

Export Support for Pre-Fabricated Armor Plate Orders

We export cut, drilled, and ready-to-install armor plates to:

  • UAE
  • Saudi Arabia
  • South Africa
  • Europe

Packaging Includes:

  • Seaworthy export pallets/crates
  • VCI anti-corrosion wrapping
  • Proper labeling with heat numbers and batch details
  • Export documentation with cutting and inspection reports (on request)

Preparing for Welding & Machining of Armor Steel

  • Share cutting/drilling drawings in advance
  • Confirm grade and thickness before fabrication
  • Discuss heat treatment needs post-fabrication (if any)
  • If welding, request our welding guideline sheet
  • Plan mock trials before bulk production

Certifications, Testing & Fabrication Support Documents

  • Mill Test Certificates (MTC)
  • Hardness Test Reports
  • Third-Party Inspection Reports (On request)
  • Fabrication layout drawings (For cut and drilled parts)
  • Welding procedure guidelines (On request)

FAQs: Welding & Machining of Armor Plates

GMAW or SMAW with low hydrogen electrodes.

Yes, especially for thickness over 10 mm.

Waterjet, plasma, or laser with controlled heat input.

Yes, using carbide tools and low RPM.

Loss of hardness in the weld zone due to excessive heat.

Not usually, but depends on project specs.

Only for thin gauges up to 8 mm.

Call, email, or WhatsApp with drawings and specifications.

Request Fabrication Support + Cut-to-Size Quote

Need help with welding and machining armor plates?

Contact Hindustan Steel Corporation today.

Ask for:

  • Welding and machining guidelines PDF
  • Cut-to-size and drilling quote
  • Hardness and quality certificates

Call Now

+91-22-66159018
+91-9820944724

Email

sales@hindustansteel.com hindustansteel1@gmail.com

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390/392, Ground Floor, Shankar Mansion, S.V.P. Road, Mumbai – 400004, India

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Armor steel isn’t one-size-fits-all. Based on mission type, threat level, region-specific compliance, and user profile (military, VIP, civilian), different armor plate grades are engineered for maximum protection, performance, and cost-efficiency.

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Whether you’re an OEM, defense contractor, or security infrastructure planner, sourcing ballistic steel isn’t just about price — it’s about lives, liability, and long-term performance

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+91-22-66159018
+91-9820944724

Email

sales@hindustansteel.com hindustansteel1@gmail.com