{"id":417,"date":"2026-06-13T12:26:16","date_gmt":"2026-06-13T12:26:16","guid":{"rendered":"https:\/\/ksl.in\/blog\/?p=417"},"modified":"2026-06-13T12:26:16","modified_gmt":"2026-06-13T12:26:16","slug":"en19-42crmo4-billet-supplier-in-india-grade-properties-sourcing-checklist","status":"publish","type":"post","link":"https:\/\/ksl.in\/blog\/en19-42crmo4-billet-supplier-in-india-grade-properties-sourcing-checklist\/","title":{"rendered":"En19 \/ 42CrMo4 Billet Supplier in India: Grade, Properties & Sourcing Checklist"},"content":{"rendered":"\n

If there is one alloy steel grade that almost every Indian forge shop buys month after month, it is En19 – better known internationally as 42CrMo4 or AISI 4140. From crankshafts and gears to shafts, studs and high-tensile fasteners, this chromium-molybdenum workhorse covers an enormous share of engineering forgings. Yet the difference between a good En19 billet and a merely acceptable one only shows up later: in ultrasonic testing, in heat-treatment response, and in field performance.<\/p>\n\n\n\n

This guide covers what En19 \/ 42CrMo4 actually is, the chemistry and mechanical properties you should specify, and a sourcing checklist for choosing the right billet supplier in India.<\/p>\n\n\n\n

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One Grade, Many Names: Equivalents You Should Know<\/strong><\/h1>\n\n\n\n

En19 is the old BS 970 designation (modern equivalent 709M40). The same chromium-molybdenum family appears under different standards worldwide:<\/p>\n\n\n\n

Standard<\/strong><\/th>Designation<\/strong><\/th><\/tr><\/thead>
BS 970 (UK)<\/td>En19 \/ 709M40<\/td><\/tr>
EN 10083-3 \/ DIN (Europe)<\/td>42CrMo4 \/ 1.7225<\/td><\/tr>
AISI \/ SAE (USA)<\/td>4140<\/td><\/tr>
JIS (Japan)<\/td>SCM440<\/td><\/tr>
IS (India)<\/td>40Cr4Mo3 (nearest equivalent)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

When you order, always confirm the governing standard on the purchase order and the mill test certificate (MTC), because permissible chemistry ranges differ slightly between standards.<\/p>\n\n\n\n

Typical Chemical Composition (%)<\/strong><\/h2>\n\n\n\n
Element<\/strong><\/th>Typical Range<\/strong><\/th><\/tr><\/thead>
Carbon (C)<\/td>0.38 \u2013 0.45<\/td><\/tr>
Manganese (Mn)<\/td>0.60 \u2013 0.90<\/td><\/tr>
Chromium (Cr)<\/td>0.90 \u2013 1.20<\/td><\/tr>
Molybdenum (Mo)<\/td>0.15 \u2013 0.30<\/td><\/tr>
Silicon (Si)<\/td>0.10 \u2013 0.35<\/td><\/tr>
Sulphur \/ Phosphorus<\/td>0.035 max each (lower on request)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Chromium gives hardenability and wear resistance; molybdenum adds strength at temperature and resists temper embrittlement. Together they let En19 achieve high strength in sections where plain carbon steels cannot.<\/p>\n\n\n\n

Mechanical Properties After Hardening and Tempering (Indicative)<\/strong><\/h2>\n\n\n\n
Property<\/strong><\/th>Typical Value (Q&T condition)<\/strong><\/th><\/tr><\/thead>
Tensile strength<\/td>850 \u2013 1,000 MPa (higher conditions possible)<\/td><\/tr>
Yield strength<\/td>\u2265 650 MPa<\/td><\/tr>
Elongation<\/td>\u2265 13%<\/td><\/tr>
Hardness<\/td>248 \u2013 302 HB (condition T)<\/td><\/tr>
Impact (Izod\/Charpy)<\/td>Good toughness retained at strength<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Exact values depend on ruling section and heat-treatment cycle – always specify the delivery condition (as-rolled, annealed, normalized, or hardened & tempered) on your order.<\/p>\n\n\n\n

Where En19 \/ 42CrMo4 Billets Are Used <\/strong><\/h2>\n\n\n\n