DY Tool Shop — Workshop hand tools and fastener | dytoolshop.com
The ordered procedure for a bolt whose head has rounded, whose hex has stripped or whose threads have seized — with the drill sizes to start with and the torque to finish at.
Start with chemistry, not force. Wire-brush the head, flood the thread line with penetrating oil and wait 10–15 minutes. Most bolts called stripped are actually seized, and oil removes the seizure that force would turn into a snapped shank.
Use a six-point socket, hammered fully home if the flats are rounded, and apply steady pressure. If that fails, an impact driver in 2–3 second bursts breaks the corrosion bond without the continuous twist that shears shanks.
When the head is beyond saving, drill for an extractor. Centre-punch first — a wandering bit is the most common failure at this stage — then open a pilot hole with a small bit. A metric jobber set runs 1.0–13.0 mm in 0.5 mm steps, so begin around 2.5–3.0 mm and step up 0.5 mm at a time until the extractor can bite.
On narrow screens, swipe or scroll the plate sideways.
Turn the screw extractor anticlockwise with a tap wrench, keeping it square to the hole. If the extractor snaps, stop: it is harder than any drill bit in a home set, and the remaining work belongs to a machine shop.
Fit the replacement bolt and tighten to specification. For passenger-car wheel nuts that means 80–140 N·m from a torque wrench, applied in a star pattern, with the exact figure taken from the vehicle placard.
Protect hearing through the impact and drilling steps: NIOSH sets 85 dB(A) as the 8-hour time-weighted average exposure limit, and impact tools exceed that level quickly. Once the bolt is out, the size chart identifies the correct socket or hex key for its replacement.
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