txstang84
15 Year Member
What hole is this?
- Thread starter JasinC19
- Start date
Blown88GT
Founding Member
txstang84
15 Year Member
The block is actually npt thread...if you try to chase the block with yours it'll cut new threads and screw the hole
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Sent from my iPhone using Tapatalk
Blown88GT
Founding Member
It's the wrong size, you can't easily measure pipe threads because of the taper.
If it's your car. You can do whatever you like, right or wrong.
Go to the hardware store & get 1/8" & 1/4" NPT plugs or nipples, brass or steel. One of them will thread right in. Or take your gauge to the hardware store & see which size it fits.
http://en.wikipedia.org/wiki/National_pipe_thread
http://en.wikipedia.org/wiki/Unified_Thread_Standard
Boydster
5 Year Member
You wont get that tap in there. If you measured the thread area at 1/2", then the thread is actually 1/4" NPT.
[edit] Blown88 has the right idea. Just take the sender to the hardware store and match it up.
You guys are right. I have a spare 1/4" NPT plug and it goes right in. I'm heading out now to get a 1/4" NPT tap. Thanks.
It is confusing when I measure the bolt at 1/2" but it is actually 1/4"... If it wasn't NPT, would the correct tap be 1/2"? I'm new to this.
It is confusing when I measure the bolt at 1/2" but it is actually 1/4"... If it wasn't NPT, would the correct tap be 1/2"? I'm new to this.
Update: I tapped the hole. All was good until a little more than halfway in and then it started getting difficult.
I tapped a little, then backed it out to see what was coming out a few times. At first it was black gunk. Then it started to get pretty difficult to turn, and I started to see metal flakes so I stopped.
When I look inside, it almost looks like the threaded hole gets narrower further in. Is this possible?
When I thread the sender in, it goes in most of the way, but there is still a thread or two visible. Is this good enough if I put thread sealer on it? If I keep tapping, it might go all the way in but I don't want to cut metal if I'm not supposed to.
Thanks,
Jason
I tapped a little, then backed it out to see what was coming out a few times. At first it was black gunk. Then it started to get pretty difficult to turn, and I started to see metal flakes so I stopped.
When I look inside, it almost looks like the threaded hole gets narrower further in. Is this possible?
When I thread the sender in, it goes in most of the way, but there is still a thread or two visible. Is this good enough if I put thread sealer on it? If I keep tapping, it might go all the way in but I don't want to cut metal if I'm not supposed to.
Thanks,
Jason
Boydster
5 Year Member
Pipe thread (NPT) is angled, so the further it's screwed in, the tighter it gets. A few threads left showing is fine... as long as it's tight. A bit of thread sealer is always nice, but just use a bit because the sender does need to get a good ground contact with the block.
When you say it is angled, do you mean the bolt diamater is narrower at the tip and thicker towards the sender? Or each individual thread is angled?
Boydster
5 Year Member
My bad... first one. From where the threads start to where they finish is tapered. IOW, the diameter of the pipe that's threaded is tapered. Take a look at the wiki ref posted earlier about NPT.
I just looked at the pic of your oil pressure sender above. It appears that the thread on the sender is not NPT (as it's not tapered), but it's known that the hole you are screwing into is tapered. This still works fine as long as the size and thread is the same.
Really, you can just screw the thing in till it's tight and you're good to go.
Thanks. I think I should be good then. If I see a puddle of oil on that side after starting the car I'll know where to look first.
