Photo · wire-macro · 1:1
Chromium-molybdenum · SAE J404
High-tensile alloy steel — strength and toughness after heat treatment.
42CrMo4EN19 (similar)Ø 4 – 19 mm
Why this grade
Chromium and molybdenum give deep hardenability, so thick sections harden through. After quench and temper it reaches high strength while staying tough — the steel for high-tensile bolts and highly loaded shafts.
High-tensile bolts (10.9 / 12.9)
Axles and drive shafts
Connecting rod bolts
Hydraulic and machine parts
Behaviour
Cold heading2/5
Machinability3/5
Hardenability5/5
Strength potential5/5
Relative comparison across the grades we supply.
Chemistry
C0.38 – 0.43
Mn0.75 – 1.00
Si0.15 – 0.35
Cr0.80 – 1.10
Mo0.15 – 0.25
S≤ 0.04
P≤ 0.04
Typical ranges per SAE J404. Actual values per mill test certificate.
Properties
Typical tensile (Q&T)≈ 900 – 1100 MPa
HardenabilityDeep, through-hardening
ToughnessHigh
How we anneal it
Spheroidise anneal
Essential before cold heading — without it the alloy is too hard to form and cracks in the die.
Annealing explainedIndustries
Enquiries
We come back with availability and a quotation — usually the same working day.