61860-NTN bearing: complete specifications & equivalents

Specification table

Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)) · extracted 2026-09-25

Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)); NTN® is a trademark of NTN Corporation, used here for identification only — mpnbase is not an authorized NTN distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at ntnglobal.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 61860-NTN model number is decoded

In the 61800-series (diameter series 8 of ISO 15) the last two digits encode the bore: 61860 carries bore code 60 = 300 mm. Outside diameter 380 mm and width 38 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 300 mm shaft, typical catalogue practice is a m6 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Large bores like the 300 mm of 61860-NTN demand clean, burr-free seats; one raised burr under a ring this size cocks the bearing and concentrates load at the raceway edge, cutting life drastically.
• Only 40.0 mm of radial section separates bore and OD on the 618xx series at 300 mm: ring flex from clamping or an oval housing bore transfers straight into raceway stress, so seat roundness matters more here than on a 6260.
• Storage matters for open bearings: 61860-NTN leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.
• Open bearings tolerate the highest speeds in the 61800-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61860 units.
• Deep-groove ball bearings tolerate only minutes of misalignment; if the 380 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 61860-NTN.
• Suffixes stack in a defined order — clearance follows the seal code, e.g. 61860-NTN-C3. No clearance suffix means normal CN clearance.
• The open 61860 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.
• The 300 mm bore places 61860 in NTN's extra-large range; the pressed-steel cage is not recommended at this diameter and NTN supplies a machined brass cage (suffix M) as the standard offering. Speed ratings are low, housing alignment is critical, and oil lubrication with a defined relubrication interval is mandatory — consult NTN engineering before sizing.
• NTN lists the grease limiting speed at 1500 r/min for 61860; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.
• At 179 kN dynamic load rating (C) and 210 kN static (C0), 7.6 kN fatigue load limit Cu, 61860 is a heavy-load bearing for industrial gearboxes and large conveyors; NTN 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 10500 g (10.5 kg), 61860 is a heavy bearing that requires a crane or hoist for handling; induction-heat the inner ring (max 120 °C) and use a mechanical puller for removal — never apply heat directly to the balls or cage.
• The 300×380×38 mm envelope of 61860 gives a D/d ratio of 1.27 and only 40.0 mm radial section height — this is an ultra-thin section where shaft deflection and housing ovality directly load the ball-raceway contact; verify shaft stiffness (target deflection under 0.05 mm) before specifying it over a 62-series.
• The 179/210 kN load ratings, 7.6 kN fatigue load limit Cu NTN lists the grease limiting speed at 1500 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 10500 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6860 on the 300×380×38 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61860 in a rated drive.
• Two NTN bearings of the same designation from different production lots can carry minor internal-geometry revisions; for paired or preloaded arrangements on one shaft, order a single lot through the NTN distributor.
• Standard catalogue stock of 61860 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.