Rethread screw socket in PR chassis....

[Tom Phillips]

...One thing I was not clear about from the first post was whether this is a vintage unit or some custom shop or re-issue. If it's not vintage, I suppose it's possible that for some bizarre reason, Fender did not use their standard screws.

I have a Deluxe Reverb Re-Issue (PCB) model on the bench right now that was made in 2019. The chassis strap bolts are 8-32.

[JJP]

You can also pop the nut out and use a regular nut, or replace the cage nut, we have those cage nuts of various sizes here at work.

I thought about that. How easy is it to "pop the nut out"? I'm assuming it's tack welded in place.

[JJP]

That is correct. And the ones used in Fender are 8-32 so NC.

One thing I was not clear about from the first post was whether this is a vintage unit or some custom shop or re-issue. If it's not vintage, I suppose it's possible that for some bizarre reason, Fender did not use their standard screws.

It's a new Custom Shop '64 Hand Wired (reissue) PR. Fabulous tones, especially with an Eminence GA10-SC64 speaker in it.

[JJP]

I'm not all that smart enough to tell you the differences, but I thought that the fine thread was an 8-36 and the coarse thread was an 8-32.

Take one of your original screws and hold it up next to the tap that you have. If they are the same, the threads will mesh with each other and fit like a glove. If they don't align, then the threads per inch are different.

I held the 8-32 tap up to the screw and while they're the same diameter, the threads to my eyes (with a magnifying glass) looked quite different. The threads on the screw (both the original one from the amp and the new set of Fender branded "Vintage" replacement screws) appear to have much deeper threads.

Rather that trash the fixed nut on the chassis, I just screwed one of the original screws back in place. It's more or less striped, but it held, and took a bit more torque with the screw driver to get it in.

As I mentioned in a previous post, I tried to thread one of the nuts that came with the new Fender branded "Vintage" replacement screws (same diameter, same thread as the original) and the nut would not thread on the tap. While I have zero experience using a tap, I figured that if the correct sized nut from the 8-32 screw wouldn't thread on to the 8-32 tap, then something is off. It's a mystery.

[Tom Phillips]

I held the 8-32 tap up to the screw and while they're the same diameter, the threads to my eyes (with a magnifying glass) looked quite different. ...

I'm starting to suspect that something is off about the 10-32 tap that you have.

[g1]

I'm starting to suspect that something is off about the 10-32 tap that you have.

He mentioned in the other thread that it was a Dewalt set. There is a 5 piece set of theirs that looks like a combined drill bit/tap, meant for impact drivers. It looks like it might be difficult to get started into an existing thread.
Not sure if that is the set he bought. Their 17 piece fractional set would be the type I am familiar with.

[JJP]

He mentioned in the other thread that it was a Dewalt set. There is a 5 piece set of theirs that looks like a combined drill bit/tap, meant for impact drivers. It looks like it might be difficult to get started into an existing thread.
Not sure if that is the set he bought. Their 17 piece fractional set would be the type I am familiar with.

What I bought is not meant for drivers. It's totally manual. Comes with a grip for the die and a similar piece for the tap.

[Greg Robinson]

As I mentioned in the other thread, I would not expect a nut to freely thread onto a tap. The cutting edges on a tap are slightly oversize, with the crest and root being sharper than the rolled threads on a nut. So long as the threads on the screw and the tap mesh, and the outer diameter of the two are similar (tap being slightly larger), then everything is fine, and you should run the tap through the chewed up fixed nut on the chassis.

[JJP]

As I mentioned in the other thread, I would not expect a nut to freely thread onto a tap. The cutting edges on a tap are slightly oversize, with the crest and root being sharper than the rolled threads on a nut. So long as the threads on the screw and the tap mesh, and the outer diameter of the two are similar (tap being slightly larger), then everything is fine, and you should run the tap through the chewed up fixed nut on the chassis.

I'm going to give it a shot. I returned the kit that I bought, so I'll have to pick up another one. Ryobi, while probably not as high quality as the DeWalt kit, at least comes in a metal case which holds all the bits and pieces. The DeWalt kit, has no case. I don't need a massive number of bits. In as much as I like buying tools, I only bit them if I need them and this is the first time I've ever had to use a tool and die kit, and it may well be the last.

[g1]

In engine work there is a lot of carbon build up so they often call for 'chasing' the thread of a bolt hole for things like cylinder head bolts. Usually when you run the tap into an existing thread, there is some resistance. So you can't expect to be able to run it through by finger pressure, but you shouldn't have to put a lot of muscle into running a tap into an existing threaded hole.
When trying to run a tap into a brand new nut, or one that has not been cross-threaded, I would expect the same, some resistance. But it should be fairly apparent if it is totally wrong.
Again though, I have noticed some of the off-shore hardware has very shallow threads, so those would offer more resistance. If you have some spare nuts around try running through a few first, to get a feel for the kind of resistance involved.

[eschertron]

What he said ^^^
I would not expect to be able to run a tap through a nut that is held between my fingers, as taps usually are used on holes in the block of some machine. A 'free' nut would have to be captured by some mechanism, such as a wrench, or vice. Some resistance, but not a lot, is to be expected. Of course, the best education is experience with the tool

Does the die run onto the screws properly? If you mentioned that, I missed it...

[JJP]

What he said ^^^
I would not expect to be able to run a tap through a nut that is held between my fingers, as taps usually are used on holes in the block of some machine. A 'free' nut would have to be captured by some mechanism, such as a wrench, or vice. Some resistance, but not a lot, is to be expected. Of course, the best education is experience with the tool

Does the die run onto the screws properly? If you mentioned that, I missed it...

That was the one thing I didn't check before returning the kit. 'm going to buy another one, and I'll definitely do one of the screws first, and then a spare nut and see how it goes.