Nicholas Hacko Watchmaker: The second most intimate watchmaker's tool: screwdrivers

Screwdriver blade - before and after polishing

Today our focus is on screwdrivers - the second most intimate watchmaker’s tool. (We'll talk about THE MOST intimate tool some other time).

What is the big deal?

1. Your mechanical watch contains at least a dozen different screws. They vary in size, shape and purpose. The range of screw sizes found in a typical watch goes from 0.50mm to 3mm so your set should contain all sizes.

How To Use Screwdriver

2. The width of the screw head slot varies greatly from calibre to calibre. Therefore, before disassembly can commence, the screwdriver’s blade must be shaped to fit the exact screw slot.

3. Blades are made of hardened carbon steel, and even with utmost care, they can chip. Being able to restore them to new condition is essential.

4. Using an incorrect screwdriver blade will cause permanent and often irreversible damage to screws. This is a sign of extremely poor craftsmanship. This is why properly trained apprentices spend weeks learning how to perfectly shape and sharpen screwdrivers - before they even attempt their first disassembly.

Bottom line: if you just bought a fine Bergeon or AF screwdriver set but don't know how to shape and sharpen your screwdrivers - you've made an amateur mistake.

Good news: here is what you need to do:

- Get yourself a proper, genuine Swiss made screwdriver's sharpening tool.
We sell Bergeon sharpening tool Ref. 2461
https://shop.clockmaker.com.au/home/112-bergeon-screwdriver-sharpener-ref-2461.html

- Get a fine polishing stone OR 3M lapping film sheet in a range of grades
https://shop.clockmaker.com.au/14-polish-clean

While a polishing stone is traditionally the abrasive of choice, my suggestion is to go for 3M lapping/polishing abrasive sheets. This is a cost saving solution, a practical and quick alternative to stones. The sheets come in a variety of grades (40 microns down to 1 micron, even as fine as 0.05 micron!. Some of the lapping 3M sheets are used in optical, electronic and other industries and are considered a military strategic product, not available to the general public. Getting the sheets imported to Australia from the US took 3 months, plenty of frustration and considerable cost, but we are pleased to be able to offer the 3M sheets to our customers at just $9 per sheet, GST included.

We use 3M daily - not just for screwdrivers but for anything - from deburring to screw head polishing. It is also a popular choice for knife blade polishing.

In stock: grades 40/30/12/9/3/1/0.05 micron, A4 sheet size. The sheets come with PSA (pressure sensitive adhesive) so they can be glued on perspex/glass plates.

What is the best size for you? That would depend on the application. We have 'developed' our own board consisting of 6 stripes (20 x 3cm) of various grades, to be used with a Bergeon screwdriver roller. Only $19.
Available at: https://shop.clockmaker.com.au/home/163-watchmaker-screwdriver-sharpening-board.html

3M film is not just your ordinarily 'sand paper' - it can be cleaned and will last you for a very long time, even if used daily.