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ASTM A325 Bolts Manufacturer & Exporter in India

Explore ASTM A325 Bolts Manufacturer & Exporter in India manufactured for demanding industrial applications with reliable strength, corrosion resistance and compliance with international standards.
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-196

Min Temp

870

Max Temp

🌡

870

Suitable for continuous service up to approximately 870°C under typical operating conditions.

⚡

620

Typical tensile strength around 620 MPa depending on product form and heat treatment.

🛡

Very Good

Very Good corrosion resistance in a wide range of industrial environments.

⚖

8

Typical density is approximately 8.0 g/cm³.

Product Overview

What are ASTM A325 Bolts?

ASTM A325 bolts are high-strength, heavy hex structural bolts manufactured from medium carbon steel, quenched and tempered to achieve superior mechanical properties. Designed specifically for structural steel connections, these bolts are widely used in steel buildings, bridges, and other civil engineering projects. ASTM A325 bolts are available in Type 1 (carbon steel), Type 2 (withdrawn), and Type 3 (weathering steel) variants, with Type 1 being the most common.

These bolts are engineered to provide reliable clamping force and shear resistance in critical load-bearing applications. They are supplied with heavy hex nuts and hardened washers, conforming to ASTM A563 and ASTM F436, respectively. ASTM A325 bolts are specified for slip-critical and bearing-type connections in accordance with AISC and RCSC guidelines.

Quick Specifications

MaterialMedium Carbon Steel, Quenched & Tempered
ASTM GradeA325 (Type 1, Type 3)
UNS NumberK10430 (Type 1)
DIN Number1.1181 (Type 1)
Material StandardASTM A325
Bolt Standard (Metric)ISO 898-1 Class 8.8
Bolt Standard (Inch)ASME B18.2.6
Thread FormUNC (Unified Coarse)
Diameter Range1/2"-1-1/2" (M12-M36)
Tensile Strength830 MPa (120 ksi) min
Yield Strength660 MPa (95 ksi) min
Hardness24-38 HRC
? All bolts supplied with full mechanical and chemical certification. Third-party inspection available.

Complete the Fastener Set

Other ASTM A325 Fastener Products Available from RealBolt

RealBolt also manufactures the complete ASTM A325 fastener range from certified alloy / carbon steel bar stock, including ASTM A325 Nuts, ASTM A325 Screws, ASTM A325 Washers, ASTM A325 Studs, and ASTM A325 Threaded Rods. All ASTM A325 fastener types are produced to ASTM with full EN 10204 MTC 3.1/3.2 documentation.
ASTM A325 Nuts
ASTM A325 Screws
ASTM A325 Washers
ASTM A325 Studs
ASTM A325 Threaded Rods

Technical Data

ASTM A325 Bolts Dimensions, Sizes & Thread Standards

ASTM A325 Bolts are available in metric M6–M100 and inch ¼″–4″ as standard. Per ASME B18.2.6 (inch series heavy hex structural bolts). Metric equivalents available per ISO 898-1 Class 8.8. Custom lengths and thread lengths available on request. All ASTM A325 bolts dimensions conform to applicable DIN, ISO, and ASME B18 standards.

Heavy Hex Structural Bolt Dimensions - Inch (ASME B18.2.6)

Nominal Size (in)Thread Pitch (UNC)Head Width (A/F, in)Head Height (in)Min Length (in)Max Length (in)
1/2137/80.34416
5/8111-1/160.4301-1/48
3/4101-1/40.5161-1/210
7/891-7/160.6021-3/410
181-5/80.688210
1-1/871-13/160.7732-1/410
1-1/4720.8592-1/210
1-3/862-3/160.9452-3/410
1-1/262-3/81.031310

Dimensional & Material Standards

StandardCoversThread
ASME B18.2.6Heavy hex structural boltsUNC
ASTM A325Mechanical & chemical requirementsUNC
ASTM A563Heavy hex nutsUNC
ASTM F436Hardened washers-
ISO 898-1Metric property class 8.8Metric
Material StandardRequirement
ASTM A325Structural bolts
ASTM A563Heavy hex nuts
ASTM F436Hardened washers
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

ASTM A325 Chemical Composition

ASTM A325 Bolts are manufactured from chromium-molybdenum alloy steel with Cr (0.8–1.1%), Mo (0.15–0.65%), and vanadium additions in B16 grades, controlled per ASTM and ASME SA-193. Cr-Mo additions raise hardenability and creep rupture strength for pressure vessel service; vanadium in B16 extends the allowable service temperature to 538°C.

Chemical Composition per ASTM A325 (Type 1)

ElementComposition (%)
Carbon (C)0.30% max
Manganese (Mn)0.60-0.90%
Phosphorus (P)0.048% max
Sulfur (S)0.058% max
Silicon (Si)0.15-0.30%
Copper (Cu)0.35% max
Nickel (Ni)0.25% max
Chromium (Cr)0.04% max
Molybdenum (Mo)0.10% max
? All heats verified by spectrographic analysis. Full traceability and certification provided.

Why ASTM A325 Alloy Composition Matters for Bolts

Medium Carbon Steel — Strength & Ductility
The controlled carbon and manganese content ensures high tensile and yield strength, while maintaining ductility for reliable clamping and shear resistance in structural connections.
Low Phosphorus & Sulfur — Improved Toughness
Strict limits on phosphorus and sulfur reduce the risk of embrittlement and improve the bolt’s toughness, especially under dynamic or impact loading conditions.
Silicon — Enhanced Hardenability
Silicon content improves hardenability and uniformity of mechanical properties after quenching and tempering, ensuring consistent performance across all bolt sizes.

Fastener Performance

ASTM A325 Bolts Mechanical Properties & Torque Reference

The table below lists mechanical properties and torque reference for ASTM A325 Bolts per ASTM. ASTM A325 bolts achieve 620 MPa tensile strength, with hardness, yield, and elongation values verified by NABL-accredited testing and reported in the EN 10204 MTC.

Bolt SizeDry (Nm)Lubricated (Nm)Clamp Load (kN)
1/2"1209538
5/8"23018561
3/4"41033090
7/8"660530125
1"990790181
1-1/8"14001120246
1-1/4"19801580318
1-3/8"27002160405
1-1/2"35502840509
?? Anti-galling: Use zinc-based or molybdenum anti-seize for large diameter bolts. Lubricated values assume K=0.16. Always follow AISC/RCSC torque procedures for structural connections.

Industry Applications

ASTM A325 Bolts Applications — Industries & End Uses

ASTM A325 Bolts from RealBolt are specified across oil and gas pressure vessels, power generation, and petrochemical where very good corrosion resistance and 620 MPa tensile strength are required for reliable fastener performance. Click each industry below for detailed application examples.
ASTM A325 bolts are the standard for bolted connections in steel building frames, bridge girders, and truss assemblies. Used for slip-critical and bearing-type joints in accordance with AISC and RCSC specifications.
Heavy hex bolts for lattice tower connections, substation bus structures, and high-voltage transmission line supports where high strength and vibration resistance are required.
Anchor bolts and structural fasteners for wind turbine towers, solar panel support frames, and renewable energy infrastructure, providing reliable performance under dynamic loading.
Structural bolts for crane booms, gantry frames, and heavy machinery bases, ensuring secure assembly and resistance to fatigue and shock loads.

ASTM A325 Bolts Standards & International Certifications

ASTM A325 Bolts from RealBolt Engineering Industries are manufactured to internationally recognised fastener dimensional standards covering thread form, tolerances, strength grades, and quality requirements. Every batch ships with EN 10204 MTC 3.1/3.2, hardness test certificate, dimensional inspection report, and proof load test records — available on request for all orders.
Standards
DIN 931 DIN 933 DIN 960 DIN 961 DIN 6914 ISO 4014 ISO 4017 ISO 8676 ISO 8765 ASME B18.2.1 EN 14399 EN 15048 EN ISO 4014 EN ISO 4017 BS EN ISO 4014 BS 3692 BS 4190 IS 1363 IS 1364 IS 3757 SAE J429 UNI 5737 UNI 5739 CSN 021101 PN 82101
Certifications
ISO 9001:2015CE MarkingEN 10204 3.1EN 10204 3.2Third-Party Inspection

Buy ASTM A325 Bolts from India's Leading Manufacturer — Get a Competitive Quote Today

Partner with RealBolt — India’s leading manufacturer of certified ASTM A325 Bolts — for competitive pricing, EN 10204 MTC 3.1/3.2 documentation, and fast Mumbai dispatch. Standard sizes are ex-stock; custom dimensions accepted with 2–3 week lead time. Request your quote today.
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Answers for Buyers

ASTM A325 Bolts — Frequently Asked Questions

Browse expert answers to common questions about ASTM A325 Bolts from RealBolt — covering ASTM A193 grade, proof load, creep ratings, cryogenic L7 limits, coating options, and EN 10204 documentation. Contact our technical team directly for project-specific guidance on ASTM A325 bolts selection and pricing.
ASTM A325 bolts comply with ASTM A325 for mechanical and chemical properties, ASME B18.2.6 for dimensions, ASTM A563 for heavy hex nuts, and ASTM F436 for hardened washers. Metric equivalents are available per ISO 898-1 Class 8.8 and DIN EN 14399-4 for structural bolting assemblies.
Yes, ASTM A325 bolts can be supplied hot-dip galvanized, mechanically galvanized, or zinc-plated for enhanced corrosion resistance. Galvanizing is performed per ASTM F2329 or ASTM B695. Always specify coating requirements at the time of order to ensure compliance with project specifications.
ASTM A325 Type 3 bolts (weathering steel) are specifically designed for outdoor use and develop a protective oxide layer. Type 1 bolts can be galvanized for corrosion protection. For highly corrosive or marine environments, consider ASTM A490 or stainless steel alternatives.
Standard sizes (1/2″-1-1/4″) are available ex-stock with no formal MOQ – single pieces can be supplied for urgent needs. Custom sizes or coatings may require a minimum order of 50-100 pieces. Project pricing available for large quantities.

Industrial Cities We Serve:

  • Ahmedabad
  • Aurangabad
  • Bengaluru
  • Chennai
  • Coimbatore
  • Faridabad
  • Gandhidham
  • Greater Noida
  • Gurugram
  • Hazira
  • Hosur
  • Hyderabad
  • Jamnagar
  • Jamshedpur
  • Ludhiana
  • Mumbai
  • Mundra
  • Mysuru
  • Nagpur
  • Nashik
  • Navi Mumbai
  • Noida
  • Pune
  • Rajkot
  • Sanand
  • Surat
  • Thane
  • Tiruppur
  • Vadodara
  • Visakhapatnam

Countries We Export To:

  • US
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  • Mexico
  • Germany
  • UK
  • France
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  • Spain
  • Netherlands
  • Belgium
  • Poland
  • Sweden
  • Norway
  • Denmark
  • Turkey
  • UAE
  • Saudi Arabia
  • Qatar
  • Oman
  • Kuwait
  • Bahrain
  • South Africa
  • Egypt
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  • Singapore
  • Malaysia
  • Indonesia
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  • South Korea
  • Japan
  • Brazil