A quick guide on cleaning up threads.
There may be many reasons to need to clean up threads, here are a couple that come to mind.
Used and abused: these poor bastards were only trying to transmit motion, a threads job. Rust and a build up of debris in the threads can ‘seize’ the hope of movement. Almost unbelievable advertising will show a quick squirt of ‘Super Juice’ and you are off to the next steps in your life, most of us know this is bs. Do your best to clean with a wire brush, manual or rotating. Once the debris is out then add your ‘Super Juice’ (penetrating lubricant of choice)…now the stuff has half a change to get into the ‘work area’ between the stud and nut.
-Powered wire wheel, a great tool that can be a time saver or an alligator… use caution not to ‘wear’ away the parent material by staying in one spot too long. Mashing the tops of the threads over can also be done, easier on fine threads…and we won’t get into flinging bits across the shop so fast that they disappear forever…or wire bits stuck into your epidermis or worse.
-Thread file, great specialty tool. These expensive buggars come in many different forms, like any tool buy or borrow quality. One of my favorites and PIA at the same time, my Blue Point unit has 8 different thread pitches on it, as many times I have grabbed it to do a quick fix, I have put it back in the file drawer as it didn’t have the desired pitch on it. I swear the tool makers do this on purpose, sell more.
-Triangle file, economy at the smartest choice. This is in my mind my go-to, because mostly of what stated about a real thread file (50% of time it doesn’t have the correct pitch, and cheepo me only has 1 unit, not the whole entire set). The biggest drawback of a triangle file is that it truest is the wrong ‘form’ to use on a thread. Most of the threads ‘we’ are interested in fixing up are 60 deg included angle, a triangle file has 3 sides which makes that 130 deg included angle. With this foresight, you may only wish to use this to take out the large ‘dings’ or ‘rags’ at the tops (peaks) of the threads. As this 120 deg will remove ‘strength’ and give ‘too much’ clearance for an accurate thread. A little spot cleaned up should not be the end of the world, your choice to clean up or replace it. Now for the triangle file, for cleaning up damaged threads under 5/8” I use a very small file 4”, the tip of this is very close to a point.
-Tap or Die Nut, this is great if you have these for the correct size. Typically I would call these expensive, nice to borrow…respect these if you get that opportunity. Do not let them ‘bang’ or ‘rub’ against others or hardened tools. Many times I find the die nuts will cut more material than I am comfortable with so I resort to a thread file (haha) or the trusty triangle file. I will use a tap when the opportunity is there, Taper tap, plug tap or bottoming tap (look this up), they all have a certain place they excel at. Help save the tap, use thread cutting fluid of some sort, ATF at the very least (WD-40 is not a cutting fluid) and the use of a T-handle should help keep the program running straight.
-Specialty tools, there are likely many things that could be added here… in my file drawer there is a short piece of 3/32” welding rod bent in a U with a 90 deg arm bent outwards each way. The arms are sharpened to a point, this is made to fit into a particular size threaded hole to be twisted in to knock out the mud and crud before I would attempt to run a tap into these holes. This worked for me at the time.
At the end; whether cleaning out all the tapped holes of a block back from the machine shop, or brand new chromed parts, threads need to be clean. Damaged threads or threads with ‘extra’ debris is then will cause issues…and sometimes that can cost dearly. Hope some of this helps…please feel free to add.
Greg
There may be many reasons to need to clean up threads, here are a couple that come to mind.
Used and abused: these poor bastards were only trying to transmit motion, a threads job. Rust and a build up of debris in the threads can ‘seize’ the hope of movement. Almost unbelievable advertising will show a quick squirt of ‘Super Juice’ and you are off to the next steps in your life, most of us know this is bs. Do your best to clean with a wire brush, manual or rotating. Once the debris is out then add your ‘Super Juice’ (penetrating lubricant of choice)…now the stuff has half a change to get into the ‘work area’ between the stud and nut.
-Powered wire wheel, a great tool that can be a time saver or an alligator… use caution not to ‘wear’ away the parent material by staying in one spot too long. Mashing the tops of the threads over can also be done, easier on fine threads…and we won’t get into flinging bits across the shop so fast that they disappear forever…or wire bits stuck into your epidermis or worse.
-Thread file, great specialty tool. These expensive buggars come in many different forms, like any tool buy or borrow quality. One of my favorites and PIA at the same time, my Blue Point unit has 8 different thread pitches on it, as many times I have grabbed it to do a quick fix, I have put it back in the file drawer as it didn’t have the desired pitch on it. I swear the tool makers do this on purpose, sell more.
-Triangle file, economy at the smartest choice. This is in my mind my go-to, because mostly of what stated about a real thread file (50% of time it doesn’t have the correct pitch, and cheepo me only has 1 unit, not the whole entire set). The biggest drawback of a triangle file is that it truest is the wrong ‘form’ to use on a thread. Most of the threads ‘we’ are interested in fixing up are 60 deg included angle, a triangle file has 3 sides which makes that 130 deg included angle. With this foresight, you may only wish to use this to take out the large ‘dings’ or ‘rags’ at the tops (peaks) of the threads. As this 120 deg will remove ‘strength’ and give ‘too much’ clearance for an accurate thread. A little spot cleaned up should not be the end of the world, your choice to clean up or replace it. Now for the triangle file, for cleaning up damaged threads under 5/8” I use a very small file 4”, the tip of this is very close to a point.
-Tap or Die Nut, this is great if you have these for the correct size. Typically I would call these expensive, nice to borrow…respect these if you get that opportunity. Do not let them ‘bang’ or ‘rub’ against others or hardened tools. Many times I find the die nuts will cut more material than I am comfortable with so I resort to a thread file (haha) or the trusty triangle file. I will use a tap when the opportunity is there, Taper tap, plug tap or bottoming tap (look this up), they all have a certain place they excel at. Help save the tap, use thread cutting fluid of some sort, ATF at the very least (WD-40 is not a cutting fluid) and the use of a T-handle should help keep the program running straight.
-Specialty tools, there are likely many things that could be added here… in my file drawer there is a short piece of 3/32” welding rod bent in a U with a 90 deg arm bent outwards each way. The arms are sharpened to a point, this is made to fit into a particular size threaded hole to be twisted in to knock out the mud and crud before I would attempt to run a tap into these holes. This worked for me at the time.
At the end; whether cleaning out all the tapped holes of a block back from the machine shop, or brand new chromed parts, threads need to be clean. Damaged threads or threads with ‘extra’ debris is then will cause issues…and sometimes that can cost dearly. Hope some of this helps…please feel free to add.
Greg
