Technical Archive

Breitling
Chronomat 40 GMT A323982B1B1A1— lug 20mm

Breitling Chronomat 40 GMT A323982B1B1A1: 20mm strap. Alligator, box calf, shell cordovan and rubber, cut and stitched in Milano. Choose your leather.

Chronomat 40 GMT Stainless Steel / Black / Qatar

Artisanal Note

"This model requires a precise 20mm lug width to preserve the original sartorial balance."

Technical Specifications

Breitling A323982B1B1A1
Lug Width
20 mm

The essential strap measurement.

Browse 20mm straps →
Reference

A323982B1B1A1

Movement

Breitling caliber Caliber 32 Hours, Minutes, Seconds, Additional 24 Hour Hand (adjustable) | Date

The Heritage

The Breitling Chronomat 40 GMT A323982B1B1A1 combines 40 years of evolution from the original 1984 Chronomat design. The 40mm stainless steel case features the signature muscular silhouette with screw-down lugs and rider tabs on the bezel at 12, 3, 6, and 9 o'clock. The independent GMT function adds a 24-hour hand adjustable without stopping the main movement. Powered by Caliber 32 Breitling movement with hours, minutes, seconds, date, and independent 24-hour hand, this watch balances presence and comfort. Lug width is 20mm.

FAQ

What is the lug width of the Breitling Chronomat 40 GMT A323982B1B1A1?

The Breitling Chronomat 40 GMT A323982B1B1A1 has a lug width of 20mm. This measurement should be taken with a digital calliper positioned inside the lugs at the narrowest point closest to the case. Verifying this figure before purchasing an aftermarket strap is essential, as even half a millimetre of discrepancy will result in a visible gap between the lug and the strap end.

What is the best strap for the Breitling Chronomat 40 GMT?

The ideal choice depends on the intended context. For formal or business wear, an alligator strap with Mississippiensis or Hornback grain complements the case architecture and the texture of the bezel. For everyday sporting use, vegetable-tanned calfskin offers durability and develops a personal patina over time. A nylon NATO strap is well suited to summer and casual settings, while vulcanised rubber is the technical option for those who keep the watch on during physical activity or water exposure.

How do you change the strap on a Breitling Chronomat 40 GMT?

Strap replacement on the Chronomat 40 GMT uses standard 20mm springbars. It is advisable to use a double-ended springbar tool to lever safely inside the lugs, avoiding scratches on the satin-finished case. Remove the springbar on the caseback side first, then slide out the strap. For a risk-free operation on a watch of this calibre, consulting a watchmaker or the Casati Milano atelier is recommended.

Are there aftermarket straps compatible with the Breitling Chronomat 40 GMT A323982B1B1A1?

Yes. Compatible aftermarket straps must have a 20mm attachment width with straight or slightly tapered ends suited to the Chronomat's lug geometry. Milano Straps offers a curated selection of handcrafted 20mm straps in various materials — alligator, calfskin, shell cordovan and NATO — manufactured to the same dimensional specifications as original Breitling straps, ensuring a correct fit with no gap between case and strap.

How long does a leather strap last on a Breitling Chronomat 40 GMT?

Longevity depends on leather quality, tanning method and daily use. A quality vegetable-tanned calfskin strap typically lasts 2–4 years with daily wear; alligator, owing to the density of its scales and penetrating dye, can exceed 5 years if kept away from prolonged moisture. Shell cordovan offers the greatest resistance to deformation. The Casati Milano guarantee covers manufacturing defects for 18 months, regardless of the material selected.