KM Series Bearing Lock Nuts are bearing accessories manufactured to DIN 981 / ISO 2982-2. 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 KM Series Bearing Lock Nuts?
KM Series Bearing Lock Nuts are bearing accessories defined by DIN 981 / ISO 2982-2. 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
Lock nuts and lock washers are carbon or stainless steel; adapter and withdrawal sleeves are mild steel, slotted and threaded to draw a tapered bore onto a plain shaft; shaft seals are nitrile as standard, FKM for temperature and chemical service, PTFE where neither will run. Match the accessory to the bearing series it locates, not to the shaft diameter alone.
Typical Applications
Locating, clamping and sealing a bearing on its shaft and in its housing: lock nuts and washers, adapter and withdrawal sleeves, and shaft seals. Read the full application guide for KM Series Bearing Lock Nuts →
Pricing
KM Series Bearing Lock Nuts are supplied to order. Pricing starts from approximately US$1.50 per piece for standard sizes in the standard material for the series; final pricing depends on size, material, finish and order quantity (MOQ applies). Submit your exact configuration with the quote form above.
Specifying the KM Series Bearing Lock Nuts
For the machines and duties this type is actually specified for, see where km series bearing lock nuts 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.