Vintage Altrax Mainspring No. 307 – 1.85 mm × 0.0975 mm × 8 mm – Unbreakable

Vintage Altrax Mainspring No. 307 – 1.85 mm × 0.0975 mm × 8 mm – Unbreakable Swiss Made NOS

Description:
Genuine vintage Altrax mainspring No. 307, Swiss Made. A high-quality unbreakable and non-deforming mainspring, ideal for servicing or restoring small 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. 307

• Height: 1.85 mm

• Thickness (strength): 0.0975 mm

• Length: 256 mm

• Barrel diameter: 8 mm

• Material: Tempered unbreakable steel

• Brand: Altrax

• Country of manufacture: Switzerland

Condition:

• New old stock (NOS) – unused.

• Packaging shows minor age-related wear.

Summary:
A genuine Swiss-made Altrax unbreakable mainspring No. 307, providing outstanding durability and precision for smaller manual-wind Swiss movements. Perfect for watchmakers, collectors, and restorers.

Postage & Shipping:
As usual, this item will be packaged carefully and dispatched with tracking. International shipping is available through the eBay Global Shipping Programme (GSP).