Screwdriver Set

Specification

Technical parameters

Overview

A watch screwdriver is not a small screwdriver. The blade must fill the slot almost exactly — too narrow and it cams out and rounds the slot, too wide and it will not seat and chews the screw head and the surrounding plate. A set covers the range in small increments, typically 0.50 mm to 3.00 mm.

The second variable is the blade profile. Standard blades are parallel for screws that sit on top of a plate; countersunk blades are tapered for screws whose heads sit below the surface. Using the wrong profile is the most common cause of a chewed screw head that should never have been damaged.

Handle design is not cosmetic. A screwdriver with a rotating head lets you rest a finger on top and apply downward pressure while turning, which is what keeps the blade seated. That pressure, not torque, is what undoes a tight screw without damage.

What matters about it

• Sized in fine increments so the blade matches the slot
• Parallel and countersunk profiles for different seat depths
• Rotating head allows downward pressure while turning
• Blades are re-sharpenable, not disposable
• Anti-magnetic options exist for sensitive work

Practical notes

• Select the blade that fills the slot with the least play, then re-check visually before turning.
• Press down harder than you turn. Pressure keeps the blade seated; torque does not.
• Dress a rounded blade immediately — a worn blade ruins every screw it touches afterwards.
• If a screw head is already damaged, stop and consider a screw slotting file rather than forcing it.

Compatible with