D. Gray D&D - HEAVY DUTY KNURLING TOOL KIT

[Dusty]

@YYCHM Hey Craig time to put your tools down, step back, cool off with a hot supper and a good nights rest.
Tomorrow's another beautiful day to take a positive look at things. Just saying!

 

[Susquatch]

Bloody Hell........

This 3/8" O1 tool steel hinge pin did my tap in Doesn't look good for salvaging the hinge pin either.

Look up Walton Tap Extractor on Amazon. Pretty sure they would get this out without wrecking the part. For some reason I can't post a link today.

They have worked quite well for me over the years. Hardened fingers go down between the tap cutter edges and grip right at the break.

Better get another better tap from Peter too......

 

[6.5 Fan]

A nut and a welder works great.

 

[VicHobbyGuy]

Better get another better tap from Peter too......

And a #20 drill?

 

[Susquatch]

And a #20 drill?

This is a darn good point Vic.

@YYCHM - you should get a good threading chart or app. A good reference will list various drill sizes along with percent of thread that the drill provides.

Depending on the material and its machinability, and depending on how strong the joint needs to be, it is sometimes a significant advantage to pick a larger drill size in the chart to get less chance of breaking the tap. Here is a shot of the options for a 10-24 thread using a cutting tap on stainless or high strength steel.

This is from an app on my android. It allows me to choose my thread size, tap type, material, etc.

Keep in mind that the ideal optimum thread fit will always fail the screw first. As you increase the drill size, you move progressively closer to failing the hole threads instead. But there is a lot of room between the two. Also, the correct torque for the fastener is almost always way more than you need to achieve proper holding strength to keep the joint from coming loose. .

 

[Susquatch]

@YYCHM - I found a link to my Walton Tap Extractor Set. It's expensive on Amazon but you get a good selection of the common sizes and they do work really well.

You can prolly find them cheaper elsewhere.

I'm no darn good at welding so the nut and tack method doesn't work for me and won't work for anyone when the tap breaks off well below the surface.

Sometimes EDM is the only game in town. But I don't have EDM so I have to find someone who does.

The Walton Set has saved my bacon more often than not.

Walton Tools 18001 Tap Extractor Set https://a.co/d/84RDWHt

 

[Dusty]

@Susquatch wrote The Walton Set has saved my bacon more often than not. Walton Tools 18001 Tap Extractor Set https://a.co/d/84RDWHt

Never used Walton broken tap extractors in fact I've never broken a tap which has to be by pure luck and drill bit selection. Reading the reviews from Amazon on this tap extractor set https://a.co/d/84RDWHt leads me to believe they only work sometimes not always. Something to do with the extractor groves not being strong enough.

Could you expand further on your experience using same.

 

[gerritv]

Can't remember the last time I broke one which I credit my approach

I'll repost the charts from earlier in this thread. I print these out, slide into a plastic holder and keep in binder. All the charts that I use are in there so not faffing about remembering which app it was.
Broken taps are usually due to bending from not supporting the 'other' end (as in a a drill press/mill or tap guide), or esp. for smaller taps, hole size too tight of the metal. This is particularly important for small taps, as in anything smaller than M6 or 1/4".
Having metric drills from 1mm-6 in .1mm increments means I generally only have to look in one index instead of 3 to find a drill.
Lastly spiral point taps seem to be stronger, and don't require the tedious and bending prone quarter turn thing. I have taps from AliExpress, India, Butterfield, SKF and CTC.

 

[Dusty]

@YYCHM have my fingers and toes crossed that today will prove to be a better day for your tapping job. Stick with it my friend as I know you will.

 

[Susquatch]

@Susquatch wrote The Walton Set has saved my bacon more often than not. Walton Tools 18001 Tap Extractor Set https://a.co/d/84RDWHt

Never used Walton broken tap extractors in fact I've never broken a tap which has to be by pure luck and drill bit selection. Reading the reviews from Amazon on this tap extractor set https://a.co/d/84RDWHt leads me to believe they only work sometimes not always. Something to do with the extractor groves not being strong enough.

Could you expand further on your experience using same.

So let me begin by saying that I have FOUR sets of garbage taps. Large and small Metric and Large and Small Imperial. Yah, you read that right, they are garbage. They were all purchased in years gone by when I didn't know better. They cut crappy threads and they break easily. But except for broken ones, they are complete sets of fine and course thread taps. So they are SUPER CONVENIENT. I wish they were not. Whenever I have to thread something I grab what I have and go for it. Inevitably I break them. When I do, I don't cry about breaking the tap, I cry about losing my part! I immediately go to Varco, my local jobber shop in Chatham, and I buy a good tap. Usually Dormer but I'm not fussy about the brand name as long as they are high quality taps.

Then the problem begins - getting the broken tap out without losing the part.

Once upon a time I did that with needle nose pliers and tap extractors and a sharp awl. Then a while back, a farmer friend loaned me his Walton set. It was awesome. So I bought my own set. I have only once (that I can remember) failed to get the broken tap out. I bent the pins on the Walton with too much force, and that was that. Dead in the water. I ordered replacement parts and a week later tried again. It worked that time. Be gentle big fella.....

I have also used EDM at a local machine shop when the tap was too big for the Walton. EDM is awesome if you have access.

I think the secret to using the Walton tool is to make sure the collar is firmly against the work and then GENTLY wiggle the extractor back and forth - but mostly back - until the broken tap comes free. If you force it, it will bend and you are buying new ears.

I'd try welding if I could weld, but I cant. Certainly not on something so small. I don't have TIG. I have spent too much on welding gear already.

I'd also like to say that I agree with other comments here - The secret to good tapping is a high quality tap and excellent alignment. When I can, I use my lathe or my mill or my drill press. But that isn't always possible especially with farm equipment. You can't put a set of disks on the mill. The tap has to go to the work. I have made a few fixtures to help keep things aligned, but that isn't always possible either. Farm repairs are hard work, on big parts, that cost a fortune. The only way around it is to pay somebody else to totally mess it up for you and then buying a new machine.....

 

[VicHobbyGuy]

Having metric drills from 1mm-6 in .1mm increments means I generally only have to look in one index instead of 3 to find a drill.

I have this set of metric drills and the quality seems pretty good.
https://www.banggood.com/Drillpro-5...etal-Drilling-p-1735296.html?cur_warehouse=CN

And my number/letter drill set is a basic 'Made in China' set. Probably similar to :
https://www.princessauto.com/en/327-pc-titanium-drill-bit-set/product/PA0008644734
or
https://www.princessauto.com/en/115-pc-titanium-drill-bit-set/product/PA0008721359
Having options for 'just a little bigger hole' is really convenient. On the beginner model engine projects I've been trying, the difference between 'too much friction' and 'sloppy and wobbly' is slight. And, of course for tapping, too- getting the right size makes a big difference, with my hodge-podge of taps. The number/letter set fills in the gaps and takes over for larger sizes.

 

[VicHobbyGuy]

For @YYCHM the good news is that a new piece of O1 should be fairly easy to source, and there's not much work invested in the part. If it were my project, I'd just make a replacement from 'mystery steel' from the scraps bin and keep pushing on, replacing that axle with O1 when I got it.
The knurler is designed to come apart for wheel swapping?

 

[VicHobbyGuy]

The secret to good tapping is a high quality tap and excellent alignment. When I can, I use my lathe or my mill or my drill press.

My new tap follower - Saturday afternoon's project- should help with this.

For tapping into flat stock held in the vise, I have a few scrap metal blocks with holes for squaring up the tap.
I keep my taps and dies, separated by size- in Ziplock bags in a small bin. Masking tape label with drill sizes for 50%/75% . One bin for inch and NPT, the other for metric.

 

[gerritv]

The secret to good tapping is a high quality tap and excellent alignment.

And proper hole size.

For places where the tap goes to the workpiece I use tapping blocks. Has various tap close clearance holes, clamp block over hole, guides tap. I have one block for NC/NF and one for metric.

 

[YYCHM]

The knurler is designed to come apart for wheel swapping?

You can change wheels without disassembling it. The wheel axles are held in place by two grub screws.

 

[trlvn]

... So let me begin by saying that I have FOUR sets of garbage taps. Large and small Metric and Large and Small Imperial. Yah, you read that right, they are garbage. They were all purchased in years gone by when I didn't know better. They cut crappy threads and they break easily.

Bit of an aside, but...is it carbon steel taps that are most likely to break?

My impression is that cheap taps are generally made of high-carbon steel. To be able to cut threads, the HC steel can't be tempered very much and is therefore still pretty brittle. HC steel should cut just fine but a little bit of bending force, and...snap!

Or am I out to lunch?

Craig

 

[Susquatch]

@YYCHM have my fingers and toes crossed that today will prove to be a better day for your tapping job. Stick with it my friend as I know you will.

Could you please post a picture of all your toes crossed?

A video of the process would also be helpful.

 

[Susquatch]

Bit of an aside, but...is it carbon steel taps that are most likely to break?

My impression is that cheap taps are generally made of high-carbon steel. To be able to cut threads, the HC steel can't be tempered very much and is therefore still pretty brittle. HC steel should cut just fine but a little bit of bending force, and...snap!

Or am I out to lunch?

Craig

I believe my junk taps are all HSS. But I also have a few triple sets (regular, bottoming, and in between) that are made of mystery metal.

 

[YYCHM]

This morning I sourced two new 10-24 taps and a pieced of SS to make a new hinge pin from @Tom Kitta (Thanks Tom!).

Man that 01 tool steel is horrible stuff to tap. I ended up going up a drill bit size to 11/64. Should have done that with the first pin when it was scritching with every turn of the tap

So one down now and one more to re-make.

 

[Former Member]

Fine center punch go, tap it out counter clockwise. As soon as a the tap is exposed small visegrips, tighten on tight and turn out.

Not sharing how I know this method