DT · MECHANICAL ENGINEERING · ISO 15 · WORKS OFFLINE

INTERACTIVE BEARING REFERENCE

Every type of bearing with full details — click any card to explore. Type any bearing code into the decoder to have it explained, then test yourself with the quiz.

0 BEARING TYPES

LIVE DECODER

BUILD-A-CODE

67 REAL DIMENSIONS

L10 LIFE CALCULATOR

ISO FIT GUIDE

FAILURE MODES

QUIZ MODE

🔍 TYPES 🔢 DECODER 🧱 BUILDER 📐 DIMENSIONS 🛠 MOUNTING ⚠️ FAILURES 🎯 QUIZ

6205-2RS

TYPE — first digit = the bearing family

SERIES — middle digits = size range & strength

BORE — last two digits = shaft-hole size (×5 mm, specials 00–03)

Type any bearing code to decode it

TRY:

Build-a-code — pick the parts, get a real bearing code

1 · FAMILY (TYPE)

2 · SERIES

3 · BORE (SHAFT, mm)

4 · SUFFIX

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Precision grades — ABEC vs ISO

⚠️ ABEC only measures dimensional accuracy — it says NOTHING about speed, noise, load or how long the bearing lasts. An ABEC-9 toy bearing can still be slow and short-lived. Higher grades mainly matter for smooth, precise rotation (spindles, robots).

Dimension lookup — real d × D × B sizes for the common series

Click a row to load its load rating into the life calculator. C = basic dynamic load rating (the number the life formula uses). Values are typical catalogue figures — always check the maker's data for exact numbers.

Bearing Life Calculator — L10

LOAD RATING C (N)

ACTUAL LOAD P (N)

SPEED n (RPM)

ELEMENT TYPE ball bearings (exponent 3)

Enter C, P and speed to see the predicted L10 life. Click a row in the table above to auto-fill C.

The 3 rules of mounting — break these and the bearing dies young

WHICH RING TURNS?

The rotating ring gets the interference (press) fit. Shaft spins → press fit on the shaft (p6). Housing spins → press fit in the housing (P7/N7). The non-rotating ring gets a light slip fit so it can't spin and wear its seat.

PUSH ON THE RING THAT IS GOING IN

Pressing onto a shaft → push on the INNER ring. Pressing into a housing → push on the OUTER ring. NEVER push through the balls — it dents the raceways (brinelling) and the bearing is scrap.

HEAT OR COLD FOR TIGHT FITS

Heat the housing ring (induction heater or oven, 80–100 °C, never above 120 °C) or chill the shaft (dry ice) so parts slide together without force. Never heat above 120 °C — seals and grease melt.

Fit calculator — pick your shaft size

Mounting methods

🖨️

Arbor press

Best for small bearings. Support the correct ring (rule 2), press slowly and straight. F1 in Schools: press 608s into 3D-printed wheels — print the hub hole ~0.1–0.2 mm smaller than the bearing OD for a plastic press fit.

🔥

Heat mounting

Expands the housing ring. Induction heaters are cleanest; an oven at 80–100 °C works for small jobs. Never above 120 °C — seals and grease melt. The hot ring drops straight on.

🧊

Cold mounting

Shrinks the shaft with dry ice or a freezer. The shaft slides into the bore, then warms and grips. Great for fitting bearings onto long shafts.

🔩

Adapter sleeves

Spherical & spherical-roller bearings often mount on a tapered adapter sleeve (suffix K). Tighten the nut to push the sleeve up the taper — the inner ring grips the shaft with no press needed.

🧴

Never hammer

A hammer blow transmits straight through the balls into the raceways = instant brinelling. If it won't go on, it's the wrong fit — don't force it.

🔧

Removal

Pull on the inner ring for shaft-mounted bearings (bearing puller), or heat the housing. Never pry between the rings — the balls get squeezed.

Failure modes — read the damage, find the cause

Lubrication — the one thing every bearing needs

Grease vs oil

Grease	Oil
Stays where you put it	Flows & carries heat away
Sealed bearings = lifetime fill	Needed above ~dN 300 000
Simpler, cleaner, cheaper	Better at very high speed
Fill only 30–50% of free space	Level should reach lowest ball

NLGI grease grades

NLGI	Consistency	Use
0–1	Soft / semi-fluid	Cold climates, gearboxes
2	Soft butter	General-purpose, bearings
3	Firm	Sealed bearings, motors
4–6	Very firm	Slow heavy jobs, blocks

Fast rule of thumb: sealed bearings (2RS/2Z) are greased for life — never open them. Open bearings: pack grease to 30–50% of the free space. Too much grease = overheating (the grease churns and heats up).