Why breaker chisels break
[placeholder: short answer, 40–60 words, for Google and AI answers]
[placeholder: guide body: causes (blank firing, wrong angle, worn bushes, wrong grade for the rock, overheating) and fixes, checked by ASI]
Compare the two ASI grades
| ASI 42CrMo4 Recommended | ASI 40CrEconomy | |
|---|---|---|
| Steel | SteelCr-Mo alloy steel to 42CrMo4 | SteelCr alloy steel, 40Cr |
| Heat treatment | Heat treatmentHardened, tempered and zone tempered: tip about 55, middle about 50, head about 45 HRC | Heat treatmentHardened and tempered. Zone tempering to be confirmed |
| Traceability | TraceabilityDot-pin serial and heat number | TraceabilitySerial and heat number |
| Best for | Best forHard rock, quarries, long shifts | Best forSofter rock, occasional use, tight budgets |
| Sizes | SizesFull range, for breakers on 5 to 60-tonne carrier excavators | Sizes135 and 140 mm only |
Cost per working hour = price ÷ hours of useful life
If an ASI 42CrMo4 chisel lasts longer than the price difference, it costs less per working hour. Ask us to work it out for your breaker.
Find the chisel for your breaker · Work out your running cost