FHF 66-4N – interchangeable spare parts

FHF 66-4N movement

Which spare parts fit the FHF 66-4N movement? For every part you can see which other calibers use the same part according to the original interchangeability list.

41Parts with interchange data

105Calibers sharing parts

Note: We have compiled this overview to the best of our knowledge and belief, based on the original interchangeability lists of FHF and the original spare-part labels. All information has been carefully checked but is provided without guarantee. Please verify the interchangeability yourself before fitting, especially the height, diameter and execution of the part.

🔧 Interchangeable parts

Part no.	Description	Also fits
182ISO 20.030	Barrel and cover	FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
195ISO 20.060	Barrel arbor	FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
206ISO 30.015	Center wheel	FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
210ISO 30.025	Third wheel	FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
227ISO 30.027	Sweep second wheel	Height 460 FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9 Height 485 FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9 Height 510 FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
245ISO 31.080	Cannon pinion with clam notch	Height 155 FHF 65 FHF 65-4 FHF 66 FHF 66-4 FHF 66-9 FHF 90-4 FHF 90-5 FHF 90-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9 FHF 905 Height 180 FHF 65 FHF 65-4 FHF 66 FHF 66-4 FHF 66-9 FHF 90-4 FHF 90-5 FHF 90-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9 FHF 905 Height 205 FHF 65 FHF 65-4 FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
255ISO 31.046	Hour wheel	Height 105 FHF 65 FHF 65-4 FHF 66 FHF 66-4 FHF 66-9 FHF 90-4 FHF 90-5 FHF 90-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9 FHF 905 Height 130 FHF 65 FHF 65-4 FHF 66 FHF 66-4 FHF 66-9 FHF 90-4 FHF 90-5 FHF 90-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9 FHF 905 Height 155 FHF 65 FHF 65-4 FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
260ISO 31.041	Minute wheel	FHF 65 FHF 65-4 FHF 66 FHF 66-4 FHF 66-9 FHF 90-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
307ISO 40.301	Regulator with adjustable stud holder, for flat hairspring	FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
311ISO 70.800	Upper cap jewel with end-piece	FHF 55 FHF 55-2 FHF 55-4 FHF 66 FHF 66-4 FHF 66-9 FHF 67 FHF 67-2 FHF 67-2N FHF 67-4 FHF 70 FHF 70-1 FHF 70-2 FHF 70-2N FHF 71 FHF 71-2 FHF 71-2N FHF 72 FHF 72-2 FHF 72-2N FHF 72-4 FHF 72-4N FHF 72-6 FHF 72-7 FHF 72-9 FHF 73 FHF 73-2 FHF 73-2N FHF 73-4 FHF 73-4N FHF 74 FHF 74-2 FHF 74-4 FHF 74-4N FHF 76 FHF 76-2 FHF 551 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9 FHF 671 FHF 671-2 FHF 671-2N FHF 675 FHF 675-4 FHF 676 FHF 676-4 FHF 701 FHF 701-2 FHF 701-2N FHF 711 FHF 711-2 FHF 711-2N FHF 725 FHF 725-4 FHF 725-4N FHF 725-7 FHF 725-9 FHF 729 FHF 729-4N FHF 729-7 FHF 735 FHF 735-4 FHF 735-4N FHF 739 FHF 739-4N FHF 745 FHF 745-4 FHF 745-4N FHF 761 FHF 761-2
330ISO 70.801	Lower cap jewel with end-piece	FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
336ISO 70.806	Upper cap-jewel with end-piece, for escape wheel	FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
342ISO 70.881	Bearing plate, jewelled, for sweep second wheel	FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
343ISO 70.891	Bearing plate, for sweep second wheel	FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
346ISO 70.807	Lower cap jewel with end-piece, f. esc. wheel	FHF 66 FHF 66-4 FHF 665 FHF 665-4 FHF 665-4N
401ISO 51.010	Winding stem	FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
407ISO 31.121	Clutch wheel	FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
410ISO 31.120	Winding pinion	FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
415ISO 31.020	Ratchet wheel	FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
420ISO 31.023	Crown wheel	FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
423ISO 81.136	Crown wheel core	FHF 66 FHF 66-4 FHF 66-9 FHF 76 FHF 76-2 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9 FHF 761 FHF 761-2
425ISO 51.120	Click	FHF 55 2e FHF 55-2 FHF 55-4 FHF 66 FHF 66-4 FHF 66-9 FHF 67 FHF 67-2 FHF 67-2N FHF 67-4 FHF 72 FHF 72-2 FHF 72-2N FHF 72-4 FHF 72-4N FHF 72-6 FHF 72-7 FHF 72-9 FHF 73 FHF 73-2 FHF 73-2N FHF 73-4 FHF 73-4N FHF 81 FHF 81-2 FHF 82 FHF 82-4 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9 FHF 671 FHF 671-2 FHF 671-2N FHF 675 FHF 675-4 FHF 676 FHF 676-4 FHF 725 FHF 725-4 FHF 725-4N FHF 725-7 FHF 725-9 FHF 729 FHF 729-4N FHF 729-7 FHF 735 FHF 735-4 FHF 735-4N FHF 739 FHF 739-4N FHF 811 FHF 811-2 FHF 821 FHF 821-4 ST 96 2e
430ISO 61.080	Click spring	FHF 28 FHF 28-2 FHF 28-2N FHF 55 FHF 55-2 FHF 55-4 FHF 66 FHF 66-4 FHF 66-9 FHF 67 FHF 67-2 FHF 67-2N FHF 67-4 FHF 70 FHF 70-1 FHF 70-2 FHF 70-2N FHF 71 FHF 71-2 FHF 71-2N FHF 72 FHF 72-2 FHF 72-2N FHF 72-4 FHF 72-4N FHF 72-6 FHF 72-7 FHF 72-9 FHF 73 FHF 73-2 FHF 73-2N FHF 73-4 FHF 73-4N FHF 74 FHF 74-2 FHF 74-4 FHF 74-4N FHF 76 FHF 76-2 FHF 81 FHF 81-2 FHF 82 FHF 82-4 FHF 281 FHF 281-2 FHF 281-2N FHF 551 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9 FHF 671 FHF 671-2 FHF 671-2N FHF 675 FHF 675-4 FHF 676 FHF 676-4 FHF 701 FHF 701-2 FHF 701-2N FHF 711 FHF 711-2 FHF 711-2N FHF 725 FHF 725-4 FHF 725-4N FHF 725-7 FHF 725-9 FHF 729 FHF 729-4N FHF 729-7 FHF 735 FHF 735-4 FHF 735-4N FHF 739 FHF 739-4N FHF 741 FHF 745 FHF 745-4 FHF 745-4N FHF 761 FHF 761-2 FHF 811 FHF 811-2 FHF 821 FHF 821-4 ST 96
435ISO 51.050	Yoke	FHF 55 FHF 55-2 FHF 55-4 FHF 65 FHF 65-4 FHF 66 FHF 66-4 FHF 66-9 FHF 72 FHF 72-2 FHF 72-2N FHF 72-4 FHF 72-4N FHF 72-6 FHF 72-9 FHF 551 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9 FHF 725 FHF 725-4 FHF 725-4N FHF 725-9 FHF 729 FHF 729-4N
440ISO 61.100	Yoke spring	FHF 55 FHF 55-2 FHF 55-4 FHF 66 FHF 66-4 FHF 66-9 FHF 67 FHF 67-2 FHF 67-2N FHF 67-4 FHF 72 FHF 72-2 FHF 72-2N FHF 72-4 FHF 72-4N FHF 72-6 FHF 72-7 FHF 72-9 FHF 73 FHF 73-2 FHF 73-2N FHF 73-4 FHF 73-4N FHF 74 FHF 74-2 FHF 74-4 FHF 74-4N FHF 98 FHF 98-1 FHF 551 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9 FHF 671 FHF 671-2 FHF 671-2N FHF 675 FHF 675-4 FHF 676 FHF 676-4 FHF 725 FHF 725-4 FHF 725-4N FHF 725-7 FHF 725-9 FHF 729 FHF 729-4N FHF 729-7 FHF 735 FHF 735-4 FHF 735-4N FHF 739 FHF 739-4N FHF 741 FHF 745 FHF 745-4 FHF 745-4N FHF 984 ST 96
443ISO 51.080	Setting lever	FHF 65 FHF 65-4 FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
443/5443ISO 51.080.06/01	Setting lever	FHF 65 FHF 65-4 FHF 66 FHF 66-4 FHF 66-9
445ISO 51.090	Setting lever spring	FHF 55 FHF 55-2 FHF 55-4 FHF 65 FHF 65-4 FHF 66 FHF 66-4 FHF 66-9 FHF 67 FHF 67-2 FHF 67-2N FHF 67-4 FHF 72 FHF 72-2 FHF 72-2N FHF 72-4 FHF 72-4N FHF 72-6 FHF 72-7 FHF 72-9 FHF 73 FHF 73-2 FHF 73-2N FHF 73-4 FHF 73-4N FHF 74 FHF 74-2 FHF 74-4 FHF 74-4N FHF 551 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9 FHF 671 FHF 671-2 FHF 671-2N FHF 675 FHF 675-4 FHF 676 FHF 676-4 FHF 725 FHF 725-4 FHF 725-4N FHF 725-7 FHF 725-9 FHF 729 FHF 729-4N FHF 729-7 FHF 735 FHF 735-4 FHF 735-4N FHF 739 FHF 739-4N FHF 741 FHF 745 FHF 745-4 FHF 745-4N
450ISO 31.100	Setting wheel	FHF 65 FHF 65-4 FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
462ISO 10.062	Minute work cock	FHF 55 FHF 55-2 FHF 55-4 FHF 65 FHF 65-4 FHF 66 FHF 66-4 FHF 72 FHF 72-2 FHF 72-2N FHF 72-4 FHF 72-4N FHF 72-6 FHF 72-7 FHF 551 FHF 665 FHF 665-4 FHF 665-4N FHF 725 FHF 725-4 FHF 725-4N FHF 725-7 FHF 729 FHF 729-4N FHF 729-7
702ISO 30.040.12	Escape wheel and pinion, pivoted, for two end-pieces	FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
703ISO 30.040.11	Escape wheel and pinion, for lower end-piece	FHF 66 FHF 66-4 FHF 66-9 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9
710ISO 40.010	Jewelled pallet fork and stat	1st execution FHF 66 FHF 66-4 FHF 66-9 FHF 81 FHF 81-2 FHF 82 FHF 82-4 FHF 665 FHF 665-4 FHF 665-4N FHF 665-9 FHF 811 FHF 811-2 FHF 821 FHF 821-4
2535ISO 13.105	Date indicator guard	FHF 72-4N FHF 73-4N FHF 74-4N FHF 665-4N FHF 725-4N FHF 735-4N FHF 739-4N FHF 745-4N ST 96-4 ST 96-4 ST 969-4
2536ISO 13.106	Additional date indicator guard	FHF 72-4N FHF 73-4N FHF 74-4N FHF 665-4N FHF 725-4N FHF 729-4N FHF 735-4N FHF 739-4N FHF 745-4N ST 96-4 ST 96-4 ST 969-4
2556ISO 33.020	Date indicator driving wheel	FHF 72-4N FHF 73-4N FHF 74-4N FHF 665-4N FHF 725-4N FHF 735-4N FHF 745-4N
2556/1ISO 33.020.06	Date indicator driving wheel	1st execution ETA 960.111 2e ST 96-4 2e ST 96-4N ST 969-4 ST 969-4N ST 974 1st execution FHF 90-4 FHF 90-5 FHF 729-4N FHF 739-4N FHF 905 2nd execution FHF 909
2557/1ISO 91.440	Date indicator, transferred	FHF 66-4 FHF 72-4 FHF 72-4N FHF 73-4 FHF 73-4N FHF 74-4 FHF 74-4N FHF 665-4 FHF 665-4N FHF 725-4 FHF 725-4N FHF 729-4N FHF 735-4 FHF 735-4N FHF 739-4N FHF 745-4 FHF 745-4N ST 96-4
2575ISO 63.030	Date jumper spring	ETA 960.111 FHF 66-4 FHF 72-4 FHF 72-4N FHF 73-4 FHF 73-4N FHF 74-4 FHF 74-4N FHF 665-4 FHF 665-4N FHF 725-4 FHF 725-4N FHF 729-4N FHF 735-4 FHF 735-4N FHF 739-4N FHF 745-4 FHF 745-4N FHF 984 FHF 984-1 ST 96-4
2576ISO 53.080	Date jumper, mounted	FHF 72-4N FHF 73-4N FHF 74-4N FHF 665-4N FHF 725-4N FHF 729-4N FHF 735-4N FHF 739-4N FHF 745-4N ST 96-4 ST 96-4 ST 969-4
2595ISO 13.111	Guard for jumper(s)	FHF 66-4 FHF 72-4 FHF 72-4N FHF 73-4 FHF 73-4N FHF 74-4 FHF 74-4N FHF 665-4 FHF 665-4N FHF 725-4 FHF 725-4N FHF 729-4N FHF 735-4 FHF 735-4N FHF 739-4N FHF 745-4 FHF 745-4N ST 96-4

Source: original interchangeability lists of FHF (checked transcription) and checked original spare-part labels · as of 2026-10-28. Height / execution: the part fits only in this height or execution.

🌀 Matching mainspring

Mainspring dimensions for FHF 66-4N (height × diameter × thickness × length) and matching mainspring in our shop:

FHF 66-4 N: 1.0 × 10.0 × 0.125 × 320 mm (GR 2473)

📄 Technical document

View the original document for FHF 66-4N online:

FHF 66-4N-665-4N – Ø 25.60 mm

🔗 Movements sharing the most parts

→ All calibers of FHF

❓ Frequently asked questions

Which FHF 66-4N spare parts also fit other movements?

For the FHF 66-4N, 41 part numbers are listed as interchangeable. Together they fit 105 other calibers – the table below shows which part fits which movement.

Which movements share the most parts with the FHF 66-4N?

The most shared parts: FHF 665-4N (45 parts), FHF 66-4 (42 parts), FHF 665-4 (41 parts).

Which mainspring fits the FHF 66-4N?

According to the Générale Ressorts catalogue (height × diameter × thickness × length): 1.0 × 10.0 × 0.125 × 320 mm (GR 2473, hand-wound, normal end hook).