Tech 101 – Thread restoration and workarounds

[DynoDave]

Tech 101 – Thread restoration and workarounds on existing hardware

HEMMINGS

[Admin]

Most informative part of the article:

"Often, U.S. threaded holes can be oversized using a metric tap (and matching bolt) of a slightly larger size and vice versa. Five-sixteenths-inch diameter threads can be tapped to 8 mm, 3/8-inch threads can be oversized to 10 mm, 5/8-inch bolts can be tapped to 16 mm, etc. This doesn’t apply to all U.S. sizes. For example, it would be difficult to find 13 mm hardware to replace a 1/2-inch bolt, but there are close equivalents that allow this switching between continents to be successful when repairing some threads"


And they are absolutely correct about "fishing" out a broken tap...rates right up there in difficulty with a broken drill bit, a broken easy-out, and a broken-off drift punch (or in one "I'll never try that again" sad incident: a broken off screwdriver shank !!....don't ask.

Good article, Dave.