RadNomad
Senior Retro Guru
[/quote]Interesting tip, not seen this before, do you think it would work with BB threads and old steel cups ?[/quote]
Never tried but yes it should work fine. Probably just need to be a bit careful when 'starting' to screw in the cup to avoid crossthreading since the thread is fine and a large diameter.
When i was a car mechanic years ago i made a few of these and they were very useful. Imagine scraping an old water pump gasket off a rusty engine block, the old pump mounting holes in the block getting contaminated with rusty coolant, old gasket and maybe ancient dried-up thread lock or sealant. Just run these 'taps' in and out a couple of times, blast of air, drop of oil, good as new!
As mentioned i suggest longer and deeper cuts than the sample photo. And only two cuts as bottle bolts are small diameter. Two long deep cuts will be better than the six tiny cuts shown in the photo. On a larger bolt like something above M10 i'd probably make three cuts. Hold the bolt head in a vice while making the cuts. I expect a steel bolt would be better than aluminium (harder wearing and won't fail in use).
Never tried but yes it should work fine. Probably just need to be a bit careful when 'starting' to screw in the cup to avoid crossthreading since the thread is fine and a large diameter.
When i was a car mechanic years ago i made a few of these and they were very useful. Imagine scraping an old water pump gasket off a rusty engine block, the old pump mounting holes in the block getting contaminated with rusty coolant, old gasket and maybe ancient dried-up thread lock or sealant. Just run these 'taps' in and out a couple of times, blast of air, drop of oil, good as new!
As mentioned i suggest longer and deeper cuts than the sample photo. And only two cuts as bottle bolts are small diameter. Two long deep cuts will be better than the six tiny cuts shown in the photo. On a larger bolt like something above M10 i'd probably make three cuts. Hold the bolt head in a vice while making the cuts. I expect a steel bolt would be better than aluminium (harder wearing and won't fail in use).