1200 Series Self-Aligning Ball Bearings are self-aligning ball bearings manufactured to ISO 15 / GB/T 281 / DIN 630. This page carries the complete boundary-dimension table — bore, outer diameter, width and corner radius for every designation in the series — with the materials, mounting and selection notes that go with it.
What Are 1200 Series Self-Aligning Ball Bearings?
1200 Series Self-Aligning Ball Bearings are self-aligning ball bearings defined by ISO 15 / GB/T 281 / DIN 630. They are selected by bearing designation and the dimensional characteristics shown below. Material, cage and sealing are specified separately from the designation and are covered further down this page.
Materials & Cage
Rings and balls are through-hardened GCr15 / 100Cr6. The cage is normally pressed steel or polyamide; the outer ring carries a common sphered raceway, so the outer ring material and its finish are what allow the bearing to align without losing raceway contact.
Typical Applications
Agricultural machinery, long line shafts, fans and conveyors, where the two housings cannot be guaranteed to be in line with each other. Read the full application guide for 1200 Series Self-Aligning Ball Bearings →
Pricing
1200 Series Self-Aligning Ball Bearings are supplied to order. Pricing starts from approximately US$3.50 per piece for standard bore sizes in bearing steel, cylindrical bore, CN clearance; final pricing depends on size, material, finish and order quantity (MOQ applies). Submit your exact configuration with the quote form above.
Specifying the 1200 Series Self-Aligning Ball Bearings
The sizes specified most often from this range are 55 mm bore, 60 mm bore, 65 mm bore and 70 mm bore. Each has its own page, so a drawing can be checked against one bore without reading the whole table above.
Material changes what this bearing tolerates far more than it changes what it costs. GCr15 Bearing Steel, Pressed Steel Cage and Polyamide Cage set out the trade-off for each grade in the same terms.
The dimensions above are fixed by ISO 15 and ISO 5753-1 — that is what makes one maker's bearing interchangeable with another's, and it is worth checking which standard a quotation is written to. For the machines and duties this type is actually specified for, see where 1200 series self-aligning ball bearings are fitted.
Manufactured in our own plant
This bearing is forged, hardened, ground, superfinished and clearance-set in-house. The stages below are where its tolerance class, its internal clearance and its noise grade are actually decided.
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01 Forging & turning
GCr15 bar and tube is cut, heated and forged into ring blanks, then turned to leave a uniform grinding allowance. Forging rather than machining from solid keeps the grain flow following the raceway, which is the surface that eventually fails.
Blank dimensions and grinding stock checked at set-up and per shift.
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02 Heat treatment
Through-hardening brings GCr15 / 100Cr6 to 58–64 HRC; carburizing case-hardens 20CrMnTi where the section is heavy or the load is shock. Rings are then stabilized so they hold size in service rather than growing in the housing.
Core and surface hardness per lot; retained austenite and dimensional stability to the ordered temperature class.
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03 Raceway grinding
Faces, bore, outer diameter and raceway are ground in sequence on separate machines. This is where the tolerance class is created: P0, P6, P5 or P4 is a grinding outcome, not a sorting outcome.
Bore and outer diameter deviation, raceway roundness and face runout measured to ISO 492 on every setup.
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04 Honing & superfinishing
The ground raceway is honed to remove the grinding lay and bring surface roughness down to a fraction of a micrometre. Raceway finish is what decides whether a lubricant film forms, and therefore what decides bearing life far more than the load rating alone.
Surface roughness Ra and waviness measured per lot.