#8-32 bolt fit in a 4.5mm hole?

[sangram]

Well, will it? The business of selecting the right bolts has me going nuts. I ordered a set of 8-32 bolts and now am getting worried they won't fit the 4.5mm holes (actually, 4.3mm) on my Seas drivers.

Which means I'm about 40 bucks down on hardware on a $300 project (already bought a lot of incorrect sizes locally).

So, will they fit? at 0.164" it works out to 4.1mm, but that's not much of a margin, really.

[AndrewT]

0.164inch easily fits through a 4.3mm diameter hole.

Are you using bolts or set screws?
Bolts are usually better.

[sangram]

Bolts and hurricane nuts on the baffle If my woodworker can make the landing zone correctly after doing the chamfer at the back, that is. Else set screws, but surely trying to avoid it like the plague as I know how painful those can be.

Thanks for the reply, Andrew. Measured the bolts that are being used now (they fit the driver holes perfectly) those were around 3.5mm (size 6 I guess), so was not able to work this out in my head and frustratingly, there isn't a single chart I could find that converted this to the millimeter scale that all driver specs seem to use.

[Andersonix]

Is this Wiki page useful?

[MoodySteve]

Your holes of 4.3mm (~0.169") are a tad smaller than the recommended 8-32 clearance hole size of 0.173" but you can probably get away with it. Is there any reason that you couldn't simply enlarge them? M4 bolts would have worked as well.

I think a table of tap and clearance drill sizes is indispensable for mechanical work.

Here's a decent one: http://www.physics.harvard.edu/servi...HREADCHART.pdf

Also, you're not likely to find a chart that gives specs for Imperial thread sizes in Metric units.

[AndrewT]

any really useful chart will always specify the diameter in both imperial and metric dimensions.

I have a glossy printed one hanging above my lathe.

It has letter/number code, inch size, fractional inch size, metric size.
Absolutely indispensable when one is looking for tapping sizes and clearance sizes and near equivalents.

[sangram]

I'm not keen on putting a hole in the rubber surround. My hands are terrible for delicate mechanical work and I have no test box to properly secure the driver.

I checked the bolts through the holes and they seem fine to me, though, so I guess I'm just about safe.

Tosh, thanks for the reply - I must've not been able to track it during the changeover to the new boards, but yes, that page seems somewhat useful.