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Alloy 20 (Carpenter 20Cb-3) Screws Manufacturer & Exporter in India

Explore Alloy 20 (Carpenter 20Cb-3) 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 Alloy 20 (Carpenter 20Cb-3) Screws?

Alloy 20 (Carpenter 20Cb-3) screws are high-performance austenitic stainless steel fasteners engineered for exceptional resistance to sulfuric acid, chloride stress corrosion cracking, and pitting. Manufactured from UNS N08020 bar stock per ASTM B473, these screws combine nickel, chromium, molybdenum, and copper for superior corrosion resistance in harsh chemical environments.

Alloy 20 screws are widely specified in chemical processing, pharmaceutical, and food industries where standard stainless steels like 304 or 316L fail. Their unique composition prevents intergranular corrosion and ensures long-term reliability in acid, chloride, and caustic service.

Quick Specifications

MaterialAlloy 20 (Carpenter 20Cb-3)
UNS NumberN08020
DIN Number2.4660
Material StandardASTM B473
Screw Standard (Metric)DIN 912 / DIN 7991 / ISO 4762
Screw Standard (Inch)ASME B18.3
Thread FormISO Metric / UNC / UNF
Diameter RangeM3-M48 / 1/8"-2"
Tensile Strength551 MPa (80 ksi) min
Yield Strength241 MPa (35 ksi) min
HardnessMax 217 HB / 22 HRC
? All material certified by NABL-accredited laboratory. PMI and intergranular corrosion test available on request.

Complete the Fastener Set

Other Alloy 20 (Carpenter 20Cb-3) Fastener Products Available from RealBolt

RealBolt also manufactures the complete Alloy 20 (Carpenter 20Cb-3) fastener range — Alloy 20 (Carpenter 20Cb-3) Bolts, Alloy 20 (Carpenter 20Cb-3) Nuts, Alloy 20 (Carpenter 20Cb-3) Washers, Alloy 20 (Carpenter 20Cb-3) Studs, Alloy 20 (Carpenter 20Cb-3) Threaded Rods — from certified bar stock per ASTM with full EN 10204 MTC 3.1/3.2 documentation and fast Mumbai dispatch.
Alloy 20 (Carpenter 20Cb-3) Bolts
Alloy 20 (Carpenter 20Cb-3) Nuts
Alloy 20 (Carpenter 20Cb-3) Washers
Alloy 20 (Carpenter 20Cb-3) Studs
Alloy 20 (Carpenter 20Cb-3) Threaded Rods

Technical Data

Alloy 20 (Carpenter 20Cb-3) Screws Dimensions, Sizes & Thread Standards

Alloy 20 (Carpenter 20Cb-3) Screws are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 912 (socket head cap), DIN 7991 (countersunk), ISO 4762. Custom lengths in 5mm increments. Inch dimensions available per ASME B18.3. All Alloy 20 (Carpenter 20Cb-3) screws dimensions are verified against applicable DIN, ISO,

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)
M30.55.53.02.5650
M40.77.04.03.0860
M50.88.55.04.01070
M61.010.06.05.01280
M81.2513.08.06.016100
M101.516.010.08.020120
M121.7518.012.010.025150
M162.024.016.014.030200
M202.530.020.017.035250
M243.036.024.019.040300
M303.545.030.022.050400
M364.054.036.027.060500
M424.563.042.032.070600
M485.072.048.036.080700

Dimensional & Material Standards

StandardCoversThread
DIN 912Socket head cap screwsMetric
DIN 7991Countersunk socket screwsMetric
ISO 4762Socket head cap screwsMetric
ASME B18.3Socket cap, button, flat headUNC/UNF
ISO 14581Hexalobular socket screwsMetric
ISO 4026Set screwsMetric
Material StandardRequirement
ASTM B473Bar/rod - UNS N08020
ASTM F2281Fastener mechanical
ASTM A194 Gr.8Nut compatibility
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

Alloy 20 (Carpenter 20Cb-3) Chemical Composition

Alloy 20 (Carpenter 20Cb-3) Screws (UNS N08020) are produced from a niobium-stabilized alloy containing nickel (32–38%), chromium (19–21%), molybdenum (2–3%), and copper (3–4%) per ASTM. Niobium stabilization at 8× minimum carbon content prevents intergranular corrosion in weld zones; the Mo + Cu combination delivers sulfuric acid immunity at all concentrations.

Chemical Composition per ASTM B473

ElementComposition (%)
Nickel (Ni)32.0-38.0%
Chromium (Cr)19.0-21.0%
Molybdenum (Mo)2.0-3.0%
Copper (Cu)3.0-4.0%
Iron (Fe)Balance
Carbon (C)0.06% max
Manganese (Mn)2.0% max
Silicon (Si)1.0% max
Niobium (Nb)8xC min-1.0% max
Phosphorus (P)0.035% max
Sulfur (S)0.035% max
? All heats verified by NABL-accredited spectrometry. PMI and intergranular corrosion test available on request.

Why Alloy 20 (Carpenter 20Cb-3) Alloy Composition Matters for Screws

Cu (3–4%) — Sulfuric Acid Resistance
Copper enhances Alloy 20’s resistance to sulfuric acid, making these screws ideal for acid process equipment and piping connections.
Nb Stabilized — Intergranular Corrosion Protection
Niobium addition prevents sensitization and intergranular attack, ensuring Alloy 20 screws maintain integrity after welding or exposure to high temperatures.
Mo (2–3%) — Pitting & Crevice Resistance
Molybdenum increases resistance to localized corrosion, especially in chloride-bearing environments, outperforming 316L screws in aggressive chemical service.

Fastener Performance

Alloy 20 (Carpenter 20Cb-3) Screws Mechanical Properties & Torque Reference

The table below lists mechanical properties and torque reference for Alloy 20 (Carpenter 20Cb-3) Screws per ASTM. Alloy 20 (Carpenter 20Cb-3) 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)
M6977.5
M8221813
M10443621
M12766130
M1618514859
M2036028893
M24620496135
M301230984216
?? Anti-galling: Use molybdenum-based or nickel-based anti-seize. Lubricated values assume K=0.16. Avoid copper-based anti-seize in acid service.

Industry Applications

Alloy 20 (Carpenter 20Cb-3) Screws Applications — Industries & End Uses

Alloy 20 (Carpenter 20Cb-3) Screws from RealBolt are specified across sulfuric acid plants, fertilizer production, and pharmaceutical where very good corrosion resistance and 620 MPa tensile strength are required for reliable fastener performance. Click each industry below for detailed application examples.
Alloy 20 screws are the industry standard for sulfuric acid piping, acid storage tanks, and process equipment in chemical plants. Their resistance to pitting, crevice, and stress corrosion cracking makes them ideal for acid transfer lines and reactor closures.
Used in process vessels, agitators, and piping systems where resistance to cleaning chemicals, organic acids, and chlorides is critical. Alloy 20 screws meet FDA and ASME BPE requirements for hygienic and corrosion-resistant fasteners.
Fasteners for brine heaters, evaporators, and reverse osmosis systems where high chloride and acidic conditions rapidly corrode standard stainless steel screws. Alloy 20 ensures long service life and minimal maintenance.
Screws for bleach plant equipment, digesters, and chemical recovery systems exposed to acidic and chloride-rich environments. Alloy 20 prevents premature failure and reduces downtime in aggressive process streams.

Alloy 20 (Carpenter 20Cb-3) Screws Standards & International Certifications

Alloy 20 (Carpenter 20Cb-3) 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, PMI (XRF), NACE MR0175/ISO 15156, and NABL-accredited lab reports — available on request for all orders.
Standards
DIN 912 DIN 913 DIN 914 DIN 915 DIN 916 DIN 6912 ISO 4762 ISO 10642 ASME B18.3 EN ISO 4762 IS 1367
Certifications
ISO 9001:2015NACE MR0175NABL LabPED 2014/68/EUMTC 3.1 / 3.2

Buy Alloy 20 (Carpenter 20Cb-3) Screws from India's Leading Manufacturer — Get a Competitive Quote Today

Partner with RealBolt — India’s leading manufacturer of certified Alloy 20 (Carpenter 20Cb-3) 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

Alloy 20 (Carpenter 20Cb-3) Screws — Frequently Asked Questions

Browse expert answers to common questions about Alloy 20 (Carpenter 20Cb-3) Screws from RealBolt — covering ASTM B473, sulfuric acid resistance, niobium stabilization, available sizes, and EN 10204 3.1 documentation. Contact our technical team directly for project-specific guidance on Alloy 20 (Carpenter 20Cb-3) screws selection and pricing.
Alloy 20 screws are available to DIN 912 (socket head cap), DIN 7991 (countersunk), ISO 4762, and ASME B18.3 (inch socket cap, button, and flat head). Set screws per ISO 4026 and hexalobular socket screws per ISO 14581 are also available. Custom thread forms (UNC, UNF, BSW) can be supplied on request.
Use a molybdenum-based or nickel-based anti-seize compound (such as Molykote P-37 or Jet-Lube SS-30) for Alloy 20 screws, especially in acid or chloride service. Avoid copper-based anti-seize in sulfuric acid environments to prevent galvanic corrosion. Lubricated torque values should be reduced by 15-20% compared to dry assembly.
Yes – Alloy 20 (Carpenter 20Cb-3) is specifically designed for resistance to sulfuric acid, chlorides, and other aggressive chemicals. It outperforms 316L and Hastelloy B2 in many acid and chloride applications, making it ideal for chemical processing, water treatment, and pharmaceutical equipment.
No formal MOQ for standard metric and inch sizes (M6-M24) held ex-stock – single piece orders are accepted for urgent maintenance. Custom sizes or non-standard threads typically require a 10 kg minimum. Quantity price breaks are available 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
  • 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