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ASTM A193 Grade B8M Screws Manufacturer & Exporter in India

Explore ASTM A193 Grade B8M Screws 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 A193 Grade B8M Screws?

ASTM A193 Grade B8M screws are high-performance fasteners manufactured from austenitic stainless steel, specifically Type 316 or its variants, conforming to ASTM A193 standards. These screws are designed for use in high-pressure, high-temperature, and corrosive environments, offering superior resistance to pitting, crevice corrosion, and chloride-induced stress corrosion cracking due to their molybdenum content.

Grade B8M screws are solution-annealed and strain-hardened to achieve the required mechanical properties, making them ideal for critical bolting applications in chemical processing, oil & gas, marine, and power generation industries. Each batch is supplied with full traceability and EN 10204 3.1 certification, ensuring compliance with international standards and project specifications.

Quick Specifications

MaterialStainless Steel 316 (AISI 316/316L)
UNS NumberS31600 / S31603
DIN Number1.4401 / 1.4404
Material StandardASTM A193 Grade B8M
Screw Standard (Metric)DIN 912 / DIN 933 / ISO 4762
Screw Standard (Inch)ASME B18.2.1 / B18.3
Thread FormISO Metric / UNC / UNF
Diameter RangeM6-M64 / ¼"-2½"
Tensile Strength515 MPa (75 ksi) min
Yield Strength205 MPa (30 ksi) min
HardnessMax 223 HB / 95 HRB
? All material certified by NABL-accredited laboratory. PMI and IGC test available on request.

Complete the Fastener Set

Other ASTM A193 Grade B8M Fastener Products Available from RealBolt

RealBolt also manufactures the complete ASTM A193 Grade B8M fastener range — ASTM A193 Grade B8M Bolts, ASTM A193 Grade B8M Nuts, ASTM A193 Grade B8M Washers, ASTM A193 Grade B8M Studs, ASTM A193 Grade B8M Threaded Rods — from certified bar stock per ASTM with full EN 10204 MTC 3.1/3.2 documentation and fast Mumbai dispatch.
ASTM A193 Grade B8M Bolts
ASTM A193 Grade B8M Nuts
ASTM A193 Grade B8M Washers
ASTM A193 Grade B8M Studs
ASTM A193 Grade B8M Threaded Rods

Technical Data

ASTM A193 Grade B8M Screws Dimensions, Sizes & Thread Standards

ASTM A193 Grade B8M Screws are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 912 (socket head), DIN 933 (hex head full thread), ISO 4762, and ASME B18.2.1. Custom lengths available in 5mm increments. Inch dimensions per ASME B18.3 and B18.2.1.

Socket Head Cap Screw Dimensions - Metric (DIN 912 / ISO 4762)

Size (M)Pitch (mm)Head Dia (mm)Head Ht (mm)Hex Socket (mm)Min L (mm)Max L (mm)
M61.0106.0510100
M81.25138.0612120
M101.51610.0816150
M121.751812.01020180
M162.02416.01425200
M202.53020.01730250
M243.03624.01940300
M303.54530.02250350
M364.05436.02760400
M424.56342.03280500
M485.07248.036100600
M565.58456.041120700
M646.09664.046140800

Dimensional & Material Standards

StandardCoversThread
DIN 912Socket head cap screwsMetric
DIN 933Hex head screws, full threadMetric
ISO 4762Socket head cap screwsMetric
ASME B18.2.1Hex cap screwsUNC/UNF
ASME B18.3Socket head cap screwsUNC/UNF
Material StandardRequirement
ASTM A193 B8MBar/rod - SS 316
ASTM A194 Gr.8MNut compatibility
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

ASTM A193 Grade B8M Chemical Composition

ASTM A193 Grade B8M Screws 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 A193 Grade B8M

ElementComposition (%)
Chromium (Cr)16.0-18.0
Nickel (Ni)10.0-14.0
Molybdenum (Mo)2.0-3.0
Manganese (Mn)2.00 max
Silicon (Si)1.00 max
Carbon (C)0.08 max
Phosphorus (P)0.045 max
Sulfur (S)0.030 max
Nitrogen (N)0.10 max
Iron (Fe)Balance
? All heats verified by NABL-accredited spectrometry. PMI and IGC test available on request.

Why ASTM A193 Grade B8M Alloy Composition Matters for Screws

Mo (2–3%) — Chloride & Acid Resistance
Molybdenum in ASTM A193 Grade B8M screws provides superior resistance to pitting and crevice corrosion in chloride-rich and acidic environments, outperforming standard 304 stainless steel in marine and chemical process applications.
Low Carbon — Weldability & Sensitization Resistance
The low carbon content (=0.08%) ensures excellent weldability and minimizes the risk of intergranular corrosion after welding, making these screws suitable for pressure vessel and piping assemblies.
Austenitic Structure — Non-Magnetic & Ductile
The fully austenitic microstructure of Grade B8M screws delivers non-magnetic properties and high ductility, allowing for reliable performance under cyclic loading and thermal expansion.

Fastener Performance

ASTM A193 Grade B8M Screws Mechanical Properties & Torque Reference

The table below lists mechanical properties and torque reference for ASTM A193 Grade B8M Screws per ASTM. ASTM A193 Grade B8M screws achieve 620 MPa tensile strength, with hardness, yield, and elongation values verified by NABL-accredited testing and reported in the EN 10204 MTC.

Screw SizeDry (Nm)Lubricated (Nm)Clamp Load (kN)
M12705628
M1617013657
M2034027289
M24590472128
M301200960206
M3621001680298
M4233002640420
M4848003840570
?? Anti-galling: Use molybdenum-based or PTFE anti-seize. Lubricated values assume K=0.16. Avoid assembly without lubrication to prevent thread galling.

Industry Applications

ASTM A193 Grade B8M Screws Applications — Industries & End Uses

ASTM A193 Grade B8M Screws 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 A193 Grade B8M screws are widely used for pressure vessel closures, heat exchanger channel covers, and reactor flanges in chemical and petrochemical plants, where resistance to acids, chlorides, and high temperatures is critical for safety and reliability.
These screws are specified for marine engine assemblies, offshore platform structures, and seawater piping systems, providing long-term corrosion resistance in saltwater and splash zone environments.
Used for bolting in refinery process units, pipeline flanges, and valve assemblies, Grade B8M screws withstand sour gas, brine, and aggressive process fluids, meeting NACE MR0175 requirements for H2S service.
Screw sets for flue gas desulphurisation (FGD) scrubbers, heat recovery steam generator (HRSG) ducting, and turbine exhaust assemblies, where high temperature and corrosive condensates demand superior stainless steel fasteners.

ASTM A193 Grade B8M Screws Standards & International Certifications

ASTM A193 Grade B8M Screws 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 84 DIN 85 DIN 912 DIN 913 DIN 914 DIN 915 DIN 916 DIN 6912 DIN 7984 DIN 7985 DIN 7991 DIN 965 ISO 4762 ISO 10642 ISO 14579 ASME B18.3 ASME B18.6.3 EN ISO 4762 IS 1363 IS 1367 SAE J933 SAE J1199
Certifications
ISO 9001:2015NACE MR0175NABL LabPED 2014/68/EUMTC 3.1 / 3.2

Buy ASTM A193 Grade B8M Screws from India's Leading Manufacturer — Get a Competitive Quote Today

Partner with RealBolt — India’s leading manufacturer of certified ASTM A193 Grade B8M Screws — 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 A193 Grade B8M Screws — Frequently Asked Questions

Browse expert answers to common questions about ASTM A193 Grade B8M Screws 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 A193 Grade B8M screws selection and pricing.
ASTM A193 Grade B8M screws are available in DIN 912 (socket head), DIN 933 (hex head full thread), ISO 4762, and ASME B18.2.1/B18.3 (inch series). Custom thread forms such as UNC, UNF, and Whitworth are available on request. All screws are supplied with full traceability and EN 10204 3.1 certification.
Use molybdenum-based or PTFE anti-seize compound (such as Molykote 1000 or Loctite LB 8014) on threads and under the head to prevent galling. Avoid copper-based anti-seize in chloride environments. Lubricated torque values should be used for assembly.
Yes – ASTM A193 Grade B8M screws are made from Type 316 stainless steel, providing excellent resistance to seawater, chlorides, acids, and a wide range of chemicals. They are the preferred choice for marine, offshore, and chemical plant bolting where 304/Grade B8 is inadequate.
No formal MOQ for standard sizes (M8-M36) held in stock – single piece orders are accepted for urgent requirements. Custom sizes or non-standard threads may require a 10 kg minimum. Quantity discounts apply at 50, 200, and 500 pieces.

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
  • 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