Grey Iron Castings (EN-GJL / DIN GG / ASTM A48): Complete Metallurgy, Machining & Sourcing Handbook
Prerequisite: The Ultimate Engineering & Sourcing Guide to Industrial Metal Castings: Grey Iron, Ductile Iron, & Steel Castings Handbook
EXECUTIVE QUICK ANSWER & METALLURGICAL OVERVIEW
TECHNICAL FUNDAMENTALS & ENGINEERING SPECIFICATION MATRIX The operational capacity and fatigue life of components inside the Grey Iron Castings category depend upon strict adherence to international material and dimensional standards (
ISO, EN, DIN, ASTM). Below is the master specification matrix.GLOBAL SOURCING ECONOMICS & INDIAN FACTUAL BENCHMARKS (
Aqua Group / Texmo) Factual benchmark: High-precision grey iron machine tool bases and pump volutes cast via automated green sand lines in the Coimbatore Foundry Corridor (Aqua Group / Texmo). When evaluating international sourcing options for Grey Iron Castings, European procurement directors can reference established Indian manufacturing leaders in the Coimbatore Corridor (Aqua Group and Texmo Industries). Operating captive automated green sand molding loops (DISAMATIC 2110) coupled with multi-axis CNC horizontal machining and 100% automated pressure testing, these groups prove definitively that Indian foundries routinely deliver European zero-defect (PPM < 10) standards at a 30%+ net landed DDP savings (PIL-008 / PRO-004).
[EXECUTIVE QUICK ANSWER: GREY IRON CASTINGS] Grey Cast Iron (EN-GJL under EN 1561 / ASTM A48) contains 2.8% to 3.8% carbon precipitated as interconnected graphite flakes. While these flakes yield low elongation (<0.8%), they provide an extraordinary specific vibration damping capacity—approx. 10x higher than carbon steel and 3-5x higher than ductile iron—making EN-GJL-250 the undisputed engineering choice for machine tool beds, CNC milling bases, pump housings, and automotive brake discs.
| Standard Grade (EN 1561) | DIN / ASTM A48 Equivalent | Tensile Strength Rm (MPa min) | Typical Hardness (HBW) | Primary Industrial Applications |
|---|---|---|---|---|
| EN-GJL-150 | DIN GG15 / ASTM A48 Class 20 | 150 | 150 – 190 HBW | Lightweight covers, non-pressure brackets, counterbalance weights. |
| EN-GJL-200 | DIN GG20 / ASTM A48 Class 30 | 200 | 170 – 210 HBW | Standard gear casings, low-pressure valves, agricultural pulley housings. |
| EN-GJL-250 | DIN GG25 / ASTM A48 Class 35 | 250 | 180 – 240 HBW | Heavy CNC machine tool beds, pump housings (Aqua Group benchmark), brake discs, engine blocks. |
| EN-GJL-300 | DIN GG30 / ASTM A48 Class 45 | 300 | 210 – 260 HBW | High-stress hydraulic cylinder blocks, heavy duty gear cases, pressure manifolds. |