1779-1729 bearing: complete specifications & equivalents

Specification table

Source: catalog reference (NTN 2203E 2026-09-25) · extracted 2026-10-01

Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN 2203E 2026-09-25); 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 1779-1729 model number is decoded

4T-1779/1729 is an NTN inch-series single-row tapered roller bearing: a separable cone-and-cup pair on the ABMA inch boundary plan, 23.812×56.896×19.368 mm (assembled width T), for a shaft of about 23.812 mm (0.937 in). Letter prefixes inherited from the inch convention mark the load family: LM reads as light-medium, HM as heavy-medium, LL as extra-light, J-prefixed codes as metric-envelope families — 1779 sits in the pure-numeric inch family. Two single-row inch sets are normally mounted as an adjusted O or X pair; the 19.368 mm T of each 4T-1779/1729 enters the spacer calculation, so the tolerance on assembled width matters as much as the bore fit. Housing fitment sequence for 4T-1779/1729: press the 1729 cup square into the 56.896 mm seat first, then bring the 1779 cone (on its 23.812 mm shaft) into adjustment — the two references are separate engineering parts that happen to ship as one set. The rollers run with their large ends against the cone's guide rib; lubricant must reach that rib face of 4T-1779/1729, not only the raceway, or the pair smears on the first overloaded start.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• At 23.812 mm (0.937 in) bore the thin cone and cup distort under an over-tight shaft nut; set the 4T-1779/1729 pair with a dial indicator on end play rather than by locknut feel.
• The pure-numeric inch family at 23.812 mm bore (56.896×19.368 mm assembled) is one of several inch families sharing similar bores; cross-series swaps change OD, T and contact angle, so match the full 1779/1729 reference at purchase.
• Replacing one half of an adjusted pair without resetting end play negates the 19.368 mm T logic: re-adjust the set and re-verify the contact pattern rather than reusing the old spacer stack.
• Inch and metric bores collide on paper — 23.812 mm is 0.937 in, not a round metric size; a metric bearing that seems 0.1 mm off will not seat on the inch shaft.
• Shaft and housing fillets must clear the ring chamfers of 1779 and 1729; use undercut shoulders so the rings seat on the face, not on a radius.
• The 47.5/46.5 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 4T-1779/1729; internal geometry legitimately differs between inch-series makers, so re-verify ratings, adjustment and the exact cone/cup references before substituting another brand on a rated drive.