6203-ZZ-FAG bearing: complete specifications & equivalents

Specification table

Source: catalog reference (HR 1 Rolling Bearings (Jan 2020)) · extracted 2026-09-25

Parameters extracted from the official FAG Rolling Bearings catalogue (HR 1 Rolling Bearings (Jan 2020)); FAG® is a trademark of Schaeffler Technologies AG & Co. KG, used here for identification only — mpnbase is not an authorized FAG/Schaeffler distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at schaeffler.com.

Cross references & equivalents

Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.

How the 6203-ZZ-FAG model number is decoded

In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6203 carries bore code 17 = 17 mm. Outside diameter 40 mm and width 12 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 17 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. Schaeffler HR 1 catalogue order number: 6203-C-2Z (FAG suffix 2Z), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• At 17 mm bore the ring mass is significant: heat 6203 on an induction heater (max 120 °C), never over an open flame, and plan puller access or a withdrawal sleeve now for the day it has to come off again.
• The 62xx light series is the default general-purpose section at 17 mm bore; before upgrading to a 6317 for extra capacity, confirm the housing accepts a 40 mm OD and 12 mm width — it is not a drop-in swap.
• ZZ shields are non-contact: 6203-ZZ-FAG blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6203-2RS for that.
• Shielded 6203-ZZ-FAG units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.
• Shaft and housing fillets must clear the bearing chamfer so the 12 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.
• Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.
• Schaeffler HR 1 lists the shielded version as 6203-C-2Z — FAG suffix 2Z, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the FAG order number when buying through a Schaeffler channel.
• FAG rates 6203 at 24600 r/min mechanical limiting speed (thermal reference speed 20100 r/min) — a high-speed range where the thermal reference speed governs continuous duty; use low-viscosity turbine oil or high-speed grease and avoid lip-contact seals entirely.
• At 17 mm bore the 6203 sits in Schaeffler's small-bore range; HR 1 ships these sizes with a pressed steel or plastic cage and P0 tolerance as standard — for instrument or spindle accuracy order the P6/P5 variant explicitly, since P0 runout figures will not hold.
• FAG rates 6203 at 11 kN dynamic (C) and 4.75 kN static (C0); this light-to-medium rating suits fractional-horsepower drives and instruments — verify the equivalent dynamic load stays well below C for conveying or gearbox duty with shock.
• At 67 g, 6203 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.
• The 17×40×12 mm envelope of 6203 gives a D/d ratio of 2.35 and 11.5 mm radial section height — a heavy FAG section for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.
• The 11/4.75 kN load ratings, mass 67 g here are Schaeffler HR 1 Rolling Bearings (Jan 2020) catalogue figures for 6203-C-2Z on the 17×40×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6203 in a rated drive. Where FAG has since released an X-life version of this size, its expanded C/C0 ratings supersede the HR 1 print values quoted here.
• Schaeffler has moved many HR 1 sizes to the X-life generation with higher C/C0 ratings; the designation is unchanged, so a current eKatalog listing for 6203 may quote higher values than the HR 1 print figures on this page — the envelope is identical either way.
• FAG standard tolerance for this size is P0 (PN); P6/P5 precision executions exist for spindle-adjacent duty but carry different order numbers in the Schaeffler system — they are not a selectable sorting of standard stock.