Photo · wire-macro · 1:1
High carbon chromium · BS 970
Bearing steel — very hard and very wear resistant.
535A99100Cr6 / SAE 52100 (similar)Ø 4 – 19 mm
Why this grade
Around 1 % carbon and 1.4 % chromium form hard chromium carbides. Hardened, it reaches well above 60 HRC and resists rolling-contact fatigue, which is why it is used for bearing balls, rollers and races.
Bearing balls and rollers
Races and bushes
Punches, gauges and tooling
Wear pins
Behaviour
Cold heading2/5
Machinability2/5
Hardenability5/5
Strength potential5/5
Relative comparison across the grades we supply.
Chemistry
C0.90 – 1.20
Mn0.30 – 0.75
Si0.10 – 0.35
Cr1.00 – 1.60
S≤ 0.05
P≤ 0.04
Typical ranges per BS 970. Actual values per mill test certificate.
Properties
Hardened≈ 60 – 65 HRC
Wear resistanceVery high
Supply stateSpheroidise annealed
How we anneal it
Spheroidise anneal (critical)
Without a full spheroidise the wire cannot be drawn or headed at all; this is the longest anneal we run.
Annealing explainedEnquiries
We come back with availability and a quotation — usually the same working day.