ASTM A307 Grade B Bolts Manufacturer & Exporter in India

Explore ASTM A307 Grade B Bolts Manufacturer & Exporter in India manufactured for demanding industrial applications with reliable strength, corrosion resistance and compliance with international standards.

-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 A307 Grade B Bolts?

ASTM A307 Grade B bolts are carbon steel fasteners manufactured for use in cast iron flanged joints, piping systems, and general construction. These bolts are produced from low-carbon steel and are designed for moderate strength applications, offering a minimum tensile strength of 60 ksi (414 MPa). ASTM A307 Grade B covers heavy hex bolts and studs intended for use in pressure piping, valves, and flanged fittings, making them a staple in waterworks, fire protection, and low-pressure process industries.

Unlike Grade A, which is for general purpose, Grade B is specifically intended for use in cast iron flanged joints and pressure piping, conforming to ASME B1.1 Unified Coarse (UNC) thread standards. All bolts are supplied with full traceability and mill test certification per EN 10204 3.1.

Quick Specifications

MaterialCarbon Steel
ASTM GradeA307 Grade B
UNS NumberK02200
DIN Number1.1151
Material StandardASTM A307
Bolt Standard (Metric)DIN 931 / DIN 933 / ISO 4014
Bolt Standard (Inch)ASME B18.2.1
Thread FormUNC / UNF / ISO Metric
Diameter RangeM6-M64 / ¼"-2½"
Tensile Strength414 MPa (60 ksi) min
Yield Strength207 MPa (30 ksi) min
HardnessMax 100 HB
? All bolts supplied with EN 10204 3.1 certification. Third-party inspection available on request.

Complete the Fastener Set

Other ASTM A307 Grade B Fastener Products Available from RealBolt

RealBolt also manufactures the complete ASTM A307 Grade B fastener range — ASTM A307 Grade B Nuts, ASTM A307 Grade B Screws, ASTM A307 Grade B Washers, ASTM A307 Grade B Studs, ASTM A307 Grade B Threaded Rods — from certified bar stock per ASTM with full EN 10204 MTC 3.1/3.2 documentation and fast Mumbai dispatch.

Technical Data

ASTM A307 Grade B Bolts Dimensions, Sizes & Thread Standards

ASTM A307 Grade B Bolts are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 931 (partial thread) / DIN 933 (full thread) / ISO 4014. Custom lengths available in 5mm increments. Inch dimensions per ASME B18.2.1 and AWWA C111 for waterworks.

Hex Bolt Dimensions - Metric (DIN 931 / ISO 4014)

Size (M)Pitch (mm)A/F (mm)Head Ht (mm)Min L (mm)Max L (mm)
M61.0104.012200
M81.25135.316250
M101.5176.420300
M121.75197.525400
M162.02410.030500
M202.53012.535600
M243.03615.040600
M303.54618.750800
M364.05522.5601000
M424.56526.0801000
M485.07530.01001200
M565.58535.01201500
M646.09540.01402000

Dimensional & Material Standards

StandardCoversThread
DIN 931Hex bolts, partial threadMetric
DIN 933Hex bolts, full threadMetric
ISO 4014Hex head screws, partialMetric
ISO 4017Hex head screws, fullMetric
ASME B18.2.1Hex & heavy hex boltsUNC/UNF
AWWA C111Bolts for waterworks flangesUNC
ASME B16.5Stud bolts for flangesUNC
Material StandardRequirement
ASTM A307Carbon steel bolts & studs
ASTM F568MMetric mechanical properties
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

ASTM A307 Grade B Chemical Composition

ASTM A307 Grade B 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 A307

ElementComposition (%)
Carbon (C)0.27% max
Manganese (Mn)0.60-1.20%
Phosphorus (P)0.04% max
Sulfur (S)0.15% max
Silicon (Si)0.15-0.30%
Copper (Cu)0.20% max
Iron (Fe)Balance
? All heats verified by spectrometry. Material traceability and chemical test reports supplied with every batch.

Why ASTM A307 Grade B Alloy Composition Matters for Bolts

Low Carbon Content — Weldability & Ductility
The low carbon content (=0.27%) ensures good weldability and ductility, making ASTM A307 Grade B bolts suitable for field fabrication and installation in piping systems and flanged joints.
Manganese & Silicon — Strength & Toughness
Manganese and silicon additions improve the strength and toughness of the bolts, providing reliable performance in moderate pressure and temperature applications.
Phosphorus & Sulfur Control — Prevents Brittleness
Strict limits on phosphorus and sulfur prevent embrittlement, ensuring the bolts maintain integrity under vibration and thermal cycling in piping and waterworks service.

Fastener Performance

ASTM A307 Grade B Bolts Mechanical Properties & Torque Reference

The table below lists mechanical properties and torque reference for ASTM A307 Grade B Bolts per ASTM. ASTM A307 Grade B 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)
M12604822
M1615012041
M2029523665
M2451040894
M301020816152
M3617601408219
M4227002160298
M4839003120398
?? Anti-galling: Use general-purpose anti-seize for carbon steel. Lubricated values assume K=0.16. For waterworks, use NSF-approved lubricants.

Industry Applications

ASTM A307 Grade B Bolts Applications — Industries & End Uses

ASTM A307 Grade B 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 A307 Grade B bolts are the standard for AWWA C110/C111 flanged ductile iron pipe joints, valves, and hydrants. Used in municipal water supply, fire protection systems, and wastewater treatment plants for reliable, code-compliant flange connections.
Heavy hex bolts and studs for ASME B16.5 and B16.47 flanged joints in low-pressure steam, air, and process water piping. Suitable for pressure vessel manways, covers, and nozzles where moderate strength and full traceability are required.
Anchor bolts, column base plates, and structural steel connections in commercial and industrial buildings. ASTM A307 Grade B bolts are widely used for steel-to-steel and steel-to-concrete connections in non-critical load-bearing applications.
Fastening of pumps, compressors, and mechanical equipment to foundations and skids. Used by OEMs for assembly of machinery, HVAC units, and general industrial equipment where moderate strength and cost-effectiveness are priorities.

ASTM A307 Grade B Bolts Standards & International Certifications

ASTM A307 Grade B 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.

Buy ASTM A307 Grade B Bolts from India's Leading Manufacturer — Get a Competitive Quote Today

Partner with RealBolt — India’s leading manufacturer of certified ASTM A307 Grade B 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.

Answers for Buyers

ASTM A307 Grade B Bolts — Frequently Asked Questions

Browse expert answers to common questions about ASTM A307 Grade B 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 A307 Grade B bolts selection and pricing.
ASTM A307 Grade B bolts are available to DIN 931 (partial thread), DIN 933 (full thread), ISO 4014/4017, ASME B18.2.1 (inch hex and heavy hex), and AWWA C111 for waterworks flanges. Stud bolts for ASME B16.5/B16.47 flanges are also supplied. Custom thread forms (BSW, BSF, Metric Fine) can be manufactured on request.
For carbon steel ASTM A307 Grade B bolts, use a general-purpose anti-seize compound such as molybdenum disulfide or graphite-based lubricants. For potable water or food service, use NSF-approved lubricants. Lubricated torque values should be reduced by 20% compared to dry assembly.
No – ASTM A307 Grade B bolts are designed for moderate pressure and temperature applications (up to 340°C). For high-pressure or high-temperature service, use ASTM A193 Grade B7 or equivalent alloy steel fasteners.
Standard sizes (M12-M36, ½”-1½”) 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 25 kg. Price breaks are available at 100 pcs, 500 pcs, and 1000 pcs.

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
  • Canada
  • Mexico
  • Germany
  • UK
  • France
  • Italy
  • Spain
  • Netherlands
  • Belgium
  • Poland
  • Sweden
  • Norway
  • Denmark
  • Turkey
  • UAE
  • Saudi Arabia
  • Qatar
  • Oman
  • Kuwait
  • Bahrain
  • South Africa
  • Egypt
  • Nigeria
  • Australia
  • New Zealand
  • Singapore
  • Malaysia
  • Indonesia
  • Thailand
  • Vietnam
  • South Korea
  • Japan
  • Brazil