General introduction about Le Segment A.B

The company was founded in 1927, as part of the activities of  Amédée Bollée in the Automobile Industry since 1890. Initially “Les Segments Amédée Bollée“, the company then specialised in the manufacture of piston rings for combustion engines.
In the 70’s, production was successfully diversified with the introduction of compression rings for hydraulic systems and compressors

The company has changed its name in 1989 to become “Le Segment A.B“, and has started developing high performance sealing systems (resistance to high temperatures – up to 1 000 °C -, profiles designed to optimize performance: total sealing or on the other side controlled leak).

More recently, Le Segment AB has turned to markets of high technology: aeronautics and the nuclear industry.

The company was certified ISO 9001 and EN 9100 in 2001 (aeronautics certification). The certification has been renewed in 2010.

The quality of our products is ensured by controls at every stage of production, and, when required by the client, quality controls and measures of critical dimensions are made through SPC statistical process control.

The Bollée family was the owner of the company until 1989. Since 1990, the company is a public limited company with a capital of 390 270 €, controlled by the CRONITE group through Mancelle de Fonderie at 100%.

Le Segment A.B.

Our production facilities offer a wide possibility of sizes. Diameters range from 8 mm to 3000 mm.

All cast iron and some alloys are provided by Mancelle de Fonderie. This foundry is specialised in the production of cast iron for heat treatment, piston inserts and cast iron rings...


- Straight join
- Bevel joint right
- Bayonet joint
- Hook lap join

Piston ring section
- Rectangular
- "L" shaped
- Barelled
- Keystone

Main types of rings
- Peripheral edges chamfered
- Inside edges chamfered
- Internal bevel
- Internal stepped

Edge and lips
- Metal
- Transversal cross-section
- Peripheral surface
- Edges and lips
- Plating
- Spring

Rings characteristics
- FGL F5 - F30 F51 - F52 - F63 - F54 - F56 - F57 - F68
- Z170CS
- Z200CD
- S6-5-2 ; UE12

Ring materials
In general, the ring is inserted in a groove incorporated in the piston and presses against the cylinder. It fulfils a sealing function between the pressurised and non-pressurised volumes and may also comprise a cylinder oil wiper.