6312-ZZ-NSK bearing: complete specifications & equivalents

Specification table

Source: catalog reference (NSK Rolling Bearings E1103 Part C) · extracted 2026-09-24

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 6312-ZZ-NSK model number is decoded

In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6312 carries bore code 12 = 60 mm. Outside diameter 130 mm and width 31 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 60 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NSK catalogue order number: 6312ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Interference on a 60 mm shaft plus running heat consumes radial clearance: where the shaft runs hot or the fit is tight, order 6312 with C3 clearance and re-check the residual value after mounting.
• The 63xx medium series gains rating at 60 mm bore through a 130 mm OD and 31 mm width; the heavier rolling elements also trade away some speed versus a 6212.
• Do not wash 6312-ZZ-NSK in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.
• Shielded 6312-ZZ-NSK units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.
• Deep-groove ball bearings tolerate only minutes of misalignment; if the 130 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6312-ZZ-NSK.
• The housing bore for the 130 mm OD should be round within IT7; an oval bore pinches the outer ring of 6312-ZZ-NSK and shows up later as two-point loaded raceway wear.
• NSK catalogues the shielded version as 6312ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NSK order number when buying through an NSK channel.
• At 60 mm bore 6312 is in NSK's upper general-purpose range; the pressed-steel cage is standard, but mid-section 63xx sizes at this bore can be ordered with a machined brass cage (suffix M) for heavy-shock or very-low-speed duty — confirm cage material with the NSK channel if the application sees impact loads.
• At 90 kN dynamic load rating (C) and 52 kN static (C0), 6312 is a heavy-load NSK bearing for industrial gearboxes and large conveyors; NSK expects a machined brass cage (suffix M) at this rating for shock duty, and the static C0 must be checked against any mounting or lifting loads.
• At 1720 g (1.7 kg), 6312 needs mechanical handling for mounting; NSK recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.
• The 60×130×31 mm envelope of 6312 gives a D/d ratio of 2.17 and 35.0 mm radial section height — a heavy NSK section built 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 90/52 kN load ratings, mass 1720 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6312ZZ on the 60×130×31 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6312 in a rated drive. NSK does not tabulate reference or limiting speeds in the E1103 Part C dimension tables used for this page — consult NSK's separate speed-rating tables before high-speed service.
• Keep NSK bearings in the original packaging until fitting: the wrapper carries the production lot, and the unopened shelf life of greased sealed units is typically quoted at three to five years in dry, vibration-free storage.
• Standard P0 runout from NSK is adequate up to the catalogue limiting speed on ground shaft seats; spindle or instrument positions should specify P6/P5 accuracy explicitly — it is a different order code, not a sorting of standard stock.