Bolt extractor size question.
johnott
07-18-2020, 02:59 PM
When bolt/bit extractor specs overlap should you go up or down in size?
Example:
8mm (5/16) bolt, broken off with no head.
2 Snap-on tapered bit extractors:
A 1/8 for bolt sizes 1/4 to “5/16” which requires a 9/64 drill bit
A 9/64 for bolt sizes “5/16” to 3/8 which requires an 11/64 drill bit.
My thoughts are that the slightly bigger extractor may have less chance to break/snap-off, but it requires a larger hole which weakens the sides of the bolt. This in turn may cause the bolt to bind as the extractor pushes or expands against it.
I need about 20-25 foot pounds of torque to free the bolt. I’m probably over thinking this since these tolerances are so close to each other, but I could really use someone with experience on this procedure to give me some feed back.
So, should I use the 1/8 or 9/64 inch bolt extractor? Why?
Example:
8mm (5/16) bolt, broken off with no head.
2 Snap-on tapered bit extractors:
A 1/8 for bolt sizes 1/4 to “5/16” which requires a 9/64 drill bit
A 9/64 for bolt sizes “5/16” to 3/8 which requires an 11/64 drill bit.
My thoughts are that the slightly bigger extractor may have less chance to break/snap-off, but it requires a larger hole which weakens the sides of the bolt. This in turn may cause the bolt to bind as the extractor pushes or expands against it.
I need about 20-25 foot pounds of torque to free the bolt. I’m probably over thinking this since these tolerances are so close to each other, but I could really use someone with experience on this procedure to give me some feed back.
So, should I use the 1/8 or 9/64 inch bolt extractor? Why?
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