New Holland part # 274188 is a disc lock nut (also listed as NUT or DISC LOCKN) used on the cutter bar/disc assemblies of certain older New Holland disc mowers.
Public parts listings describe it as a lock nut specifically for the discs (catalog section typically labeled “DISCS”).
Detailed dimensional specs (thread size, pitch, material grade, wrench size, etc.) are not widely published in online dealer catalogs. It is a genuine New Holland/CNH OEM part. For an exact match or aftermarket equivalent, reference the part number with a dealer or measure a sample.
The part appears in the discs section of the parts catalogs for these New Holland disc mowers. Dates are catalog production/usage ranges. Fitment should be confirmed for a specific serial number, as some notes (e.g., BSN/ASN) apply.
| Model | Type | Production Dates |
|---|---|---|
| 442 | NH Disc Mower | Jul 1977 – Dec 1995 |
| 452 | NH Disc Mower | Jul 1986 – Dec 1995 |
| 462 | NH Disc Mower | Jul 1977 – Dec 1995 |
| 463 | NH Disc Mower | Jul 1983 – Dec 1995 |
Notes from catalogs: Used as the disc lock nut (e.g., (4) on 442, (5) on 452, (6) on 462/463, with some before/after serial-number distinctions such as BSN R0525 on certain models). Related parts (e.g., blade lock nuts like 274187) are separate.
These are the classic New Holland disc mower models from the late 1970s–mid-1990s. Always verify against the official parts diagram for your exact machine serial number, as catalogs list where the part is referenced but do not guarantee fitment on every unit.