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Thread cutting,tapping etc.


Fazzman

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Hey guys,

 

Over in wigwags march giveaway thread we've been discussing tap and die sets and using them etc etc.  figured we should start a new thread so we dont blow out Wigs intentions for his thread.   Lets try and keep this thread to everything related to cutting and recutting threads.

 

 

 

 

 

For tapping holes First you must use the proper size drill,for that you referance your handy chart http://www.brokenbolt.com/images/starrett-inch-metric-tap-drill.pdf  

For example a 1/4-20 requires a #7 drill,but you can also use a #6 or a #5 thread strength is still there and its easier on the tap,any bigger than that and you lose too much thread strength.

 

Drill hole straight,preferably using a mill or drill press,can be done by hand,then lube up tap making sure it stays straight and go to town,thread it in and backoff and clear chips as you go especially in a blind hole or deep thru hole.

 

A die is used for cutting new threads,can be used to clean up threads as well.  Most tap and die sets you find around are carbon steel which arent that great(depending on the threaded material) but if you dont use them often work just fine. HSS is preferred but you will pay more best for sizes you use most,as with taps make sure to use some cutting oil.

 

To fix stripped threads you need Helicoil(thread repair kit) kits of the proper size,they come with what you need. just dont try and use the helicoil tap also known as an STI tap to tap your regular holes or you will be hosed. Also you can redrill and retap to a larger size if possible.

 

 

 

The Gearwrench tap and die handles are awesome i have a kit of those and many other styles. The Gearwrench die stocks hold hexagon dies,there are round ones too so be wary of that.  Ive tapped and threaded and rethreaded thousands of holes over my career.

 

Here's a vid i found on youtube for you:

 

 

You used to be able to get tap and die charts from Starrett for free,not sure if they still do that,looks like you can just gotta make an account now:  http://www.starrett.com/catalogs but printable ones are all over the internet. there are even phone apps too.

 

Chart of different tapstyles,useful for finding proper tap design for what applications you need. -  http://www.newmantools.com/taps/styles.htm

 

Roll form tap chart - http://balax.com/sites/default/files/Thredfloer-Class-of-Fit.pdf 

Warning,do not use roll form taps in standard cut tap holes you will be sorry,roll taps require a larger hole to be drilled.

 

More info about taps than you thought existed lol - http://www.threadcheck.com/taps-dies-cutting-tools/.

 

 

 

 

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Well, Fazzman pretty much gave a great amount of info. I'd only add tidbits here and there. I watched that vid earlier, good info in it. I also watched one where the guys showed how to use a drill press, good vid there too.

 

I have the Gearwrench 75pc Tap and Die set. Nice set to have, has most of the sizes you'd need for routine stuff. It also has an adapter so you can use round dies. I also have a thread chaser set, that has thread chasers and thread files. Those are for repairing damaged threads, and not for creating threads. They come in handy for when a thread has a nick in it or gets a little out of whack. We sell a decent thread chaser set at work (O'Reilly) and it comes in handy for most thread issues. I'll get some shots of the set and post them so everyone can see what's in it.

 

For cutting new threads nothing beats a good set, there's a lot of "cheap" sets out there, some are good most are not. The biggest issues with the lower-quality sets is the handles, they break just by looking at them. Your first step should be to buy a good tap handle set, they can be found at good prices and a good handle will make a pretty big difference in your tapping ability.

 

General Tap Handle Set...these are what I use at work, and they're fantastic.

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The tap sockets listed above by unclebud are nice,I have some at the shop, with the gearwrench set they arent needed because you can use 3/8 drive ratchet extensions with them. The sockets give a nice option if clearance is an issue.

Thread files are nice to have on hand. I have a set made by Nicholson and they are not expensive and work well,I also have a 60° universal thread file.

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The good thing about Gearwrench is that they make some of their tools with the ability to be used with some of their other tools. For example, they make an adapter kit that allows the use of a standard 3/8" extension for more reach. I've actually used them a few times for tapping holes that were in too deep for the tap to reach. Luckily the pass-through hole was big enough for the tap holder to fit, and the Gearwrench stuff worked perfectly. If I didn't have it I would have had to tear apart half the machine to get at the piece that need to be tapped. They also make their Pass-thru ratchet the same size as the tap and die holders, so if you want standard ratcheting action you can use that too. The only drawback I've found with the tap holders is for when I want to use the drill press, the tap holders have a ball-bearing in the top, so when I want to center them I have to dig out my nail set that fits the ball diameter. Not a deal-breaker at all, but I don't like grabbing 16 tools to do one thing

 

I'm about to upload a vid to show the set. Pardon my rambling like an idiot in it. You'll see the adapters and the Pass-thru ratchet that I'm talking about in the vid

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I ran out of battery and switched to the iPhone, but the vid ran long and ate my space, so the end got cut off. As I said, pardon my babbling like a moron. I'm gonna just use the vid from the camera, it's enough to see what's what. It's a great set, and the adapters, and the ability to use the Pass-thru ratchet, make it even better. IF need be I can do close-ups or shoot some pics with the DSLR. It's a tap set though, most people have seen one and know what it is.

 

 

 

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A spring loaded tap guide is something nice to have on hand for when you have a drill press or mill to use:  http://www.amazon.com/Brown-Sharpe-599-792-30-Adjustable-Tensioned/dp/B005317ZMC/ref=sr_1_1?ie=UTF8&qid=1457296831&sr=8-1&keywords=spring+loaded+tap+guide

 

When you need a guide you can clamp onto something this is handy:  http://www.amazon.com/Big-Gator-Tools-STD500NP-V-TapGuide/dp/B000ZN30U4/ref=pd_sbs_328_4?ie=UTF8&dpID=31emS4kzrdL&dpSrc=sims&preST=_AC_UL160_SR160%2C160_&refRID=1GDTXXGSV5RSPD9YBXJM

 

Here's a decent basic ratcheting tap wrench:  http://www.amazon.com/Irwin-Tools-21102--T-handle-Ratcheting/dp/B0039MNCGA/ref=sr_1_32?ie=UTF8&qid=1457297203&sr=8-32&keywords=tap+wrench

 

thread repair files:  http://www.amazon.com/Nicholson-Thread-Repair-Single-Square/dp/B001T4KRHC/ref=sr_1_3?ie=UTF8&qid=1457297799&sr=8-3&keywords=thread+file 

 

Dont forget tap lube,its highly critical that you use tapping fluid,or cutting oil. You can get cutting oil in a spray can that works pretty well. 3 in 1 oil or WD-40 can work in a pinch.  My favorite is Rapid Tap by Relton,its amazing what materials you can tap with this stuff. Tap Magic,Tapmatic and CRC make good stuff too. CRC makes the aerosol cutting oil i use. Spray can is nice because it makes less of a mess. Acid brush method works good too.

 

 

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I've always used whatever is at hand for the press, but I've kept the tap guides in my mind. I wouldn't mind having a set, just because they seem like they're totally useful for on-the-fly stuff. Most of the time I'm doing repairs away from the bench, so I typically rely on my brain telling my eyes that my hands are holding things straight. Most of the time it works. The tap handles we have at work have divots, so anything will work. My Gearwrench holders don't though, that ball bearing makes it a little harder to find something that will work. But, so far I've only used the press a few times so it hasn't been too much of a hassle.

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Nope, that's what taps are for, when you have a bad hole you can fix it. If you can't tap it, you drill it larger, tap it, and use a Helicoil. I actually did that a couple of times at work recently to fix messed-up holes on pallet jacks. Helicoil are another fun thing to play with, kinda goes along with the tap theme so if you want info about that too just ask.

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No problem,i'm happy to share what knowledge I have.

 

Yeah dont be afraid to axe questions man. :)

 

HeliCoil is just a brand name really.

If you go to any auto part or hardware store they tend to have whatever brand they carry. PermaCoil is what Napa near me sells I think. 

 

One rule of thumb about thread depth to fastener strength is tap 2 to 2.5x tap diameter. So for instance for a 1/4-20 you should be at minimum .5" deep preferably .75" or so.

It doesnt have to be exact. Full strength of a 1/4" bolt is approx 1000lbs.

 

 

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Here's my Mac TD117COMBOS set. I'd love to have a Norseman HSS set, but I just don't use them enough to justify the cost.

 

I like that this set is self contained in that every drill bit required is included. 

 

I picked ked this set up for around $200 on eBay IIRC and I'm not sure it had ever been used. 

image.jpeg

image.jpeg

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I also feel it imperative to add that a thread chaser set is an essential item in any shop.

 

T&D's are not the best tool for the job when repairing mashed up threads. Chasers re-align the existing threads with minimal loss of material compared to a T&D

image.jpeg

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Just now, Stercorarius said:

I need to get a chaser set. The taps are tricky to get aligned right. I really don't enjoy messing up head bolt threads.

 

Sears is the best place to get them. They sell the EXACT same Lang made set for around $50 that the trucks are selling for $150. And I mean it's EXACTLY the same set.

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Just now, Conductor562 said:

 

Sears is the best place to get them. They sell the EXACT same Lang made set for around $50 that the trucks are selling for $150. And I mean it's EXACTLY the same set.

This is happening tomorrow morning. This is good to know. Thanks man!

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10 minutes ago, Stercorarius said:

This is happening tomorrow morning. This is good to know. Thanks man!

 

No problem. There's a lot of stuff on the trucks that can be had for a fraction of the price elsewhere. Here's an article I did about it awhile back:

 

http://professional-power-tool-guide.com/2014/08/who-makes-what-tools/

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