Draft, not for publishing. Waiting for the mill test certificates, the spectro results on imported chisels, and a check of the grade table against each standard. Every value marked "verify" or [placeholder] must be confirmed first.
Is 42CrMo4 chisel steel available in India? Yes. Here is the proof.
42CrMo4 is made and sold in India under its equivalent names, EN19 (709M40) and SAE 4140. ASI makes its ASI 42CrMo4 chisels from it, and checks every heat's mill certificate against 42CrMo4 limits.
The same steel under different names
Each country's standard gives this chromium-molybdenum steel its own name. Their limits overlap, but they are not identical, so a steel can carry two names only when its certificate meets both.
| Grade | Standard | Molybdenum % verify | Notes |
|---|---|---|---|
| 42CrMo4 | EN 10083-3 | 0.15–0.30 | The European name buyers know |
| EN19 / 709M40 | BS 970 | 709M40: 0.25–0.35 (BS 970-3); older EN19 listings 0.20–0.35 | [placeholder: which spec ASI's mill certifies against] |
| 40Cr1Mo28 | IS 1570 (India) | about 0.20–0.35 | Indian designation close to EN19 |
| SAE / AISI 4140 | SAE J404 / ASTM A29 | 0.15–0.25 | US name |
| 42CrMo | GB/T 3077 (China) | 0.15–0.25 | The name on many imported chisels |
| SCM440 | JIS G4053 (Japan) | 0.15–0.30 | Japanese name |
| 40Cr (for contrast) | GB/T 3077 | none specified | Economy chisel steel, chromium only |
Ranges as published in common references. [placeholder: each range checked against the current standard, with the edition and date]
42CrMo4 against 40Cr: the real difference is molybdenum
Both are chromium alloy steels. 42CrMo4 adds molybdenum. In a thick chisel, 135 to 140 mm across, that does two things:
- Full hardness reaches deeper into the section, not just the surface.
- The steel keeps its hardness when it is tempered for toughness. Molybdenum steels resist softening at higher tempering temperatures.
ASI's molybdenum floor
42CrMo4 allows molybdenum from 0.15%. ASI buys its chisel steel to a 0.20% minimum. Recent heats have been around 0.22% [placeholder: heat numbers and mill certificate dates].
Imported chisels ASI tested measured about 0.17% [placeholder: how many chisels were tested, when, and the spectro report codes].
ASI keeps the spectro report behind every comparative number on this page.
Traceable to the heat of steel
Every ASI 42CrMo4 chisel carries a dot-pin serial number, model number and heat number, so it can be traced to the heat of steel it was made from.
Zone tempering targets about 55 HRC at the tip, about 50 HRC in the middle and about 45 HRC at the head.
[placeholder: a hardness report with each chisel, once ASI issues one]
Questions buyers ask
Is EN19 the same as 42CrMo4?
They are close equivalents, not the same standard. Their chemistry limits overlap but differ, for example on molybdenum. A heat of EN19 is also 42CrMo4 only when its mill certificate is inside every 42CrMo4 limit: carbon, silicon, manganese, chromium, molybdenum, phosphorus and sulphur. ASI checks that for each heat.
Why do imported chisels say 42CrMo4?
Because it is the name most buyers know. The name tells you which standard the steel was bought to. The mill certificate, and a spectro test of the chisel itself, tell you whether a given chisel meets it.
How do I know which steel my chisel is made from?
Every ASI 42CrMo4 chisel carries a dot-pin serial number and heat number. Send the serial number on WhatsApp and we tell you which heat of steel it came from. [placeholder: whether ASI shares the heat's mill certificate, and a per-chisel hardness report, once ASI issues one]
Is 40Cr a bad chisel?
No. It suits lighter, occasional work and softer rock. For hard rock and long shifts, ASI 42CrMo4 is the safer choice.
Does more molybdenum always mean a better chisel?
No. The heat treatment matters as much as the steel. That is why ASI hardens, tempers and zone tempers every 42CrMo4 chisel, so the tip, middle and head each get the hardness their job needs.
See also: what a chisel costs you per running hour.