Vintage Altrax Mainspring No. 310 – 1.80 mm × 0.11 mm × 9.5 mm – Unbreakable

Description:
Genuine vintage Altrax mainspring No. 310, Swiss Made. A high-quality unbreakable and non-deforming mainspring, ideal for servicing or restoring vintage manual-wind wristwatches.

Listing is for one mainspring only. Where multiples are available, some orders may not include the original outer packaging.

Specifications:

• Type: Unbreakable mainspring
• Reference: No. 310
• Height: 1.80 mm
• Thickness (strength): 0.11 mm
• Barrel diameter: 9.5 mm
• Material: Tempered unbreakable steel
• Brand: Altrax
• Country of manufacture: Switzerland

Condition:

• New old stock (NOS) – unused.

Summary:
A genuine Swiss-made Altrax unbreakable mainspring No. 310 offering excellent strength and reliability, suitable for mid-size vintage manual-wind Swiss wristwatches. Perfect for watchmakers, collectors, or restorers.

Postage & Shipping:
As usual, this item will be packaged carefully and dispatched with tracking. International shipping is available upon request.