I always use just plain old T-nuts unless I get the H nuts with a kit from Leland.I put a dab of 5 min epoxy on the back of each one. I never use slotted head or philips head machine screws. Always socket head cap screws in grade 5. This way when you remove the bolt you need very little downward pressure on the allen wrench . They fit in the heads and turn with ease. I also keep a stock of ball drivers for those hard to get at bolts. Short and long shafts.
Ever since I replaced sex with food I cant even get into my own pants!
I bet you could safety wire those cap heads with minimal effort.
A bit of fiddly time with a drill press would make the holes. Unless they are hardened.
My biggest worry is that when I'm dead and gone, my wife will sell my toys for what I said I paid for them.
Actually you can buy them already drilled for safety wire from some machine shops but they are a tad pricey.The Grade 5 on up are a bit hard to drill but you can if you really wanted to. I've drilled them with carbide drills but again the cost of a single carbide bit is very high and one slip with some side load and they're done! They shatter very easily!
If you use lots of coolant and go slow (not speed but feed) you can drill them with HSS Bits. Since it's generally a pretty small hole I wouldn't expect the bit to get you more then a half dozen or so.
Most times I've done it I used a premade jig to help guide the bit and keep it straight. Real small drills bend very easily and force the hole out of round or off center or break the bit!
Ever since I replaced sex with food I cant even get into my own pants!
LelandCrooks wrote:Talking to a new supplier now. I'll check.
I wasn't aware that they were a commonly available item.Used most specifically in aviation and a bit in motorsports.
I always thought you could only get them from Machine shops that specialize in specialty (ie. avation and Mil Spec fasteners).
FWIW safety wiring is grossly an overestimated application giving a false sense of security. In aviation safety wiring is used not to prevent the loss of preload of the fastener but the total loss of the fastener itself. Even the best safety wiring techniques can still allow the fastener to move slightly and if that happens the preload (torque) of the fastener is now compromised. In a device that exhibits a lot of vibration that can lead to a number of scenarios. Mainly the lose fastener can now allow the two parts to move and with prolonged movement comes wearing away of the underside of the fastener and ovalizing of the hole itself. Eventually it leads to fastener breakage or complete structural failure. If the safety wired bolt head breaks off it can be prevented from being lost or becoming another lose foreign object such as inside the compression chamber of a turbine! That would surely cause more destruction.
IMHO a small dab of blue loctight is more then enough to keep loudspeaker fasteners in place and no heat would be needed to remove the fastener either. If you dont like the loctight method you can purchase grade 5 socket head cap screws that have a nylon locking piece imbeded into the shank of the screw in the threaded area , like these.
Nylok and Blue Loctite both raise the spectre of spinning a T-nut.
Safety wiring is a royal PIA, been there, done that, but it does provide a secure bolt without friction on the T-nut.
My biggest worry is that when I'm dead and gone, my wife will sell my toys for what I said I paid for them.
There probably is one more thing to add to the T nut debacle. After mine are secured with epoxy I also run a tap through them to ensure no epoxy has gotten into the threaded area. I've also noticed on the cheaper Lowes brands that are galvanized that there is some contamination from the galvanizing process that also gets into the threads.Here a tap is very helpful prior to installation.
I tend to buy them in boxes of 50 or 100 from McMaster Carr. The quality is very good and they are priced quite reasonably.Most of the time when someone brings me a box with slipped T-nuts I find the nut has been pushed out of the wood or cross threaded. In a few instances I've forud the complete wrong screw installed.Since they were probably the China brand they actually galled and threaded into the hole. Of course they usually wont come back out either!
Ever since I replaced sex with food I cant even get into my own pants!
Ron K wrote:After mine are secured with epoxy I also run a tap through them to ensure no epoxy has gotten into the threaded area. I've also noticed on the cheaper brands that are galvanized that there is some contamination from the galvanizing process that also gets into the threads.Here a tap is very helpful prior to installation.
+1
Semi-retired: Former Australia and New Zealand Authorised BFM cab builder.
Another option to install the nuts is to use a bolt, run a nut up to the top, install a flat washer. Then to install the H-nut, insert the H-nut into the wood, thread the bolt into the H-nut at least five threads and draw the H-nut in by using a wrench (or socket if it will fit) on the upper nut. This will allow for any type of bolt use (flat, Phillips, Robertson, Hex cap ....to draw it in.
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Semi-retired: Former Australia and New Zealand Authorised BFM cab builder.