# what size t nuts for subwoofer screw holes



## newtitan (Mar 7, 2005)

I need some tnuts since the woofers I got for the mean time are rather heavy and will fire down (sw8200's)

anyone know what size typically is the best for t nuts


I was thinking 10-32 

will this work okay?


like these

http://cgi.ebay.com/machine-screw-a...hZ016QQcategoryZ47095QQtcZphotoQQcmdZViewItem


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## chad (Jun 30, 2005)

10-32 will be fine. In fact it's kinda standard.

Chad


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## newtitan (Mar 7, 2005)

okay thanks Ill get those then, thanks


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## toolfan91 (Dec 7, 2005)

I personally like using 1/4"-20s, but thats me


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## newtitan (Mar 7, 2005)

do these ?threaded inserts work better? than tnuts


10-32 33/64" 9/32" M5 50 92105A670 5.00 
1 1/4"-20 33/64" 23/64" M6 100 92105A675 9.46


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## toolfan91 (Dec 7, 2005)

Never tried those, but id rather have a good contact patch with a tnut on the opposite side of where the subwoofer is mounted to secure the sub.


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## ClinesSelect (Apr 16, 2006)

T-nuts can crack MDF if mounted near the edge. To keep that from happening, I've glued on a piece of plywood (because it does not crack) and then hammed the t-nut into the plywood. Frankly I like the hurricane nuts better when working near the edge of MDF.


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## NaamanF (Jan 18, 2006)

Yes they work a lot better. WWW.Mcmaster.COM .


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## Beau (Oct 8, 2005)

AzGrower is the resident "expert" on these. You might want to PM him.


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## newtitan (Mar 7, 2005)

okay so tnuts rip the edges up around speker holes, that sounds about right lo, hurricane nuts are better cool


so should I get the 1/4"-20 or the 10-32"

ive always just used screws, but I want to do it right this time so im asking noob questions 

thanks for the help guys


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## shinjohn (Feb 8, 2006)

Having had alot of experience with fasteners, some comments...
- As mentioned, pull out strength is alot higher on flanged nuts like the T-nut or Hurricane nut. The inserts would tend to fail at the wood interface, whereas the flanged variety would fail at the metal thread.
- Keep drill hole size in mind for your application; from largest to smallest drill hole size, given the same screw thread application: Insert, then Hurricane nut, then T-nut. This is important because the space between your driver cutout and the mounting screw holes can sometimes be minimal (make the driver cut-out as tight as possible) I think for a sub, the insert is impractical.
- I've found that the smaller T-nuts (#6 & #8) typically won't split MDF near the edge. This is due to the smaller teeth, as well as smaller flange, which keeps the teeth further away from your cut-out. YMMV.
- Hurricane nuts have higher push in force than T-nuts. Glueing of expoxying the T-nuts in can prevent this problem too.
- Flanged nuts: watch the flange size or screw hole positions if you plan to brace the front baffle close to the drivers. (or if you plan to use a very small front baffle)
- Larger screw/nut combos have the potential to leak air more.
- T-nuts and threaded inserts are readily available at practically any local home center, or Home Depot.

So, the net of it is that I typically use the _smallest_ nut/screw combo that will do the job. From an engineering perspective, English threads in the #6-#10 range (x8 on most drivers, too!) should be able to hold even the heaviest of drivers. I epoxy the T-nuts in to prevent push out. Hurricane nuts are great too, but I haven't seen them anywhere except PE. I also prefer stainless phillips head hardware.....

FYI, the triple Arc 10D4 STi sub in my Pbase gallery uses #6 T-nuts and they hold great.

Hope this helps. GL.


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## gnesterenko (Mar 17, 2011)

GOing to revive this very very old thread. So I got my Shiva X2 in yesterday and my fiberglass boxes are ready to go. SO I started looking at how to mount it. Was thinking drywall screws at first, but since I'm using threaded inserts for (almost) every hole on my amp rack, I figured it would be nice and more secure to use the same in the MDF ring of the sub box. The box is built for a recessed install, so another wider, carpeted MDF ring around the actual mounting one.

And naturally I'm trying not to destroy the rings while drilling holes, or to split the MDF. I would LIKE to use self-tapping threaded inserts I got (8-32) but I'm a bit worried about the low amount of tolerance between the edge of the hole and where the nuts would go. So just looking for feedback. Has anyone used self tapping nuts for subwoofer mounting in MDF?
Should I spring for some Tnuts instead?

Posting from work, so need this disclaimer:
"The views expressed here are mine and do not reflect the official opinion of my employer or the organization through which the Internet was accessed."


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