Tap and die (1 Viewer)

[B1oodyBuzzard]

Probably an easy one for some the more experienced.

What size tap do I need for the square plug on the knuckle? I want to clean up the threads.

Also while I’m thinking about it. What die do I need for lug nut studs? I’d like to clean up the threads for the spare tire mount.

Thanks in advance.

 

[igotta40]

Just buy a thread file and match up the correct threads on it with your part. They come in SAE and metric. Amazon.

 

[charliemeyer007]

I would just do that plug with a needle file. Measure the plug to determine the size and pitch. Maybe timmyisinthewell can provide the numbers for the plug and lug nuts.

 

[B1oodyBuzzard]

The plug isn’t what is fouled the hole on the knuckle

 

[timmyisinthewell]

While I can provide p/n's, sadly I don't have any reference in my microfiche set that would show nut, bolt, plugs, washers, etc. size, length, thread pitch, or any other helpful info. Sure wished I did!

 

[charliemeyer007]

You are back to measuring that plug. My guess is its some metric british pipe thread. In the last week or two there was a thread about fittings.

 

[B1oodyBuzzard]

M12x1.25 ordered for the stud.

 

[mattressking]

Knuckle is BSPT, memory serves me it is 3/8-19

 

[B1oodyBuzzard]

This is it you think? I was expecting M##x1.25 or what ever.

Knuckle is BSPT, memory serves me it is 3/8-19

 

[Godwin]

An alternative to the square head plugs

Where did you find a brass allen head plug for the fill port?

McMaster-Carr. $4.12 ea.... 3/8 BSPT Item#4860K133

I've installed these on my 60 and they work fine.

 

[mattressking]

This is it you think? I was expecting M##x1.25 or what ever.


View attachment 3727923

It is 3/8-19 tap, so yes. I have one at home - I just had to rattle my brain if it’s 3/8 which @Godwin confirmed.

Toyota alternative 3/8-19 with Allen head plug is:

90344-53011

 

[73FJ40]

It is 3/8-19 tap, so yes. I have one at home - I just had to rattle my brain if it’s 3/8 which @Godwin confirmed.

Toyota alternative 1/4-19 with Allen head plug is:

90344-52003


Are the threads tapered? If so, the leading threads will be slightly smaller in diameter than the trailing threads. The taper is less than 2 degrees, so don't expect a big difference.

Assuming it is the 3/8 BSPT (tapered) you need a tap with the Rc (sometimes just R) designation, not G.

G is for BSPP, or parallel threads, which are not tapered and won't seal like tapered threads. The photo in post 9 clearly indicates "G" on the tap, and you can see the threads aren't tapered. I don't think this plug needs to do any real sealing, except to keep water and mud out of the knuckle.

If you need to confirm the 3/8 size, google BSPT thread tables, and compare the dimensions on your pipe plug to the table. There are major differences between 1/4, 3/8, and 1/2. These fractional identities have nothing to do with the dimensions of the threads.

 

[charliemeyer007]

I know a pipe fitter. He told me a story about a job he had to go out on. The untrained workers had used the thread protector that came on the pipe to assemble a big ethanol still for processing sugar beet waste to make gasoline additive. Anyway the plant blew up killing a few workers the during start up. Tapered threads or regular ones need to be on both sides.

Do you remember that sky walk that collapse killing a bunch of folks during its dedication ceremony? So it turn out the construction people used cut thread bolts to hold up the platform not the rolled thread ones specified by designer.

 

[mattressking]

This photo shows a tap with 1/4 - 19 threads, not 3/8 - 19.

Thanks for catching that! Updated with correct pn.

 

[4Cruisers]

I know a pipe fitter. He told me a story about a job he had to go out on. The untrained workers had used the thread protector that came on the pipe to assemble a big ethanol still for processing sugar beet waste to make gasoline additive. Anyway the plant blew up killing a few workers the during start up. Tapered threads or regular ones need to be on both sides.

Do you remember that sky walk that collapse killing a bunch of folks during its dedication ceremony? So it turn out the construction people used cut thread bolts to hold up the platform not the rolled thread ones specified by designer.

Another related story.

A few years ago my wife and I couldn't figure out why there was a very faint natural gas odor in the basement every once in a while. It turns out that one of the fittings used in the hard line extension at the rear of the gas dryer that had belonged to my brother-in-law wasn't a flare fitting. Even though the joint had plenty of thread sealant tape, there was still a tiny leak.

 

[73FJ40]

Another related story.

A few years ago my wife and I couldn't figure out why there was a very faint natural gas odor in the basement every once in a while. It turns out that one of the fittings used in the hard line extension at the rear of the gas dryer that had belonged to my brother-in-law wasn't a flare fitting. Even though the joint had plenty of thread sealant tape, there was still a tiny leak.

Just like people here on MUD that try to use Teflon tape to seal brake line leaks. They need to understand the science behind double-flared tubing and corresponding seats in female fittings.

 

[45Dougal]

You are back to measuring that plug. My guess is its some metric british pipe thread. In the last week or two there was a thread about fittings.

British standard pipe threads aren't metric, and metric threads aren't uniquely British.
Britain made the leap to metric in the 70s, but some of these old "imperial" standards hang around due to global popularity - you can't expect the world to change every single threaded pipe union overnight I guess.

 

[charliemeyer007]

Yea Whitworth

 

[pb4ugo]

British standard pipe threads aren't metric, and metric threads aren't uniquely British.
Britain made the leap to metric in the 70s, but some of these old "imperial" standards hang around due to global popularity - you can't expect the world to change every single threaded pipe union overnight I guess.

Bspt isn't metric. but it's still foreign to me.. When the US wanted to go towards metric, they should have just jumped in with both feet. Instead, it was a luke warm attempt and now we are constantly converting one way or the other, even though the distance is the same. Our vehicles now have a mixture of both types of fasteners. Genius.

 

[Grayscale]

Do you remember that sky walk that collapse killing a bunch of folks during its dedication ceremony? So it turn out the construction people used cut thread bolts to hold up the platform not the rolled thread ones specified by designer.

So, maybe a die isn't ideal on lug-nut studs, perhaps they aren't cut threads, maybe they are rolled? I really doubt that the hubs use cut-thread studs. Not as critical on the spare tire carrier, but, depending on what the need is, rust or just mangled, or how much spare tire you intend to carry, you might want to consider the full scope of the issue. For example, you can't fix a rusty stud, the rust already has likely compromised the 'root' of the thread, and a die, or file only hides the problem. A die might cut into the rolled part of the thread-root, or not, depending on the root-diameter of the stud and the OD of the tap? Maybe rust isn't the OP's issue, and it is all good? Fastener fatigue is real common on these rigs.