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Tap and die set


daverclasper
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Hi. Bought a cheap imperial set (Clarkes), a while back. have used a few taps to clean up threads and been ok.

One stud off off the head, that holds the inlet manifold (on Vitesse Mk1 2 Litre) was a bit burred on the manifold side, so thought I'd clean it up. A tap that fitted nicely in the nut (1/2" ac flats) was  5/16" fine, so checked with factory manual and stud is apparently 5/16" fine.

Not used any dyes before. Fitted 5/16" fine, in holder and used WD 40. Was quite stiff and cutting of a fair bit of metal, I thought it wasn't right, but stupidly carried on .

The stud now visibly narrower and the nut a rattling fit.

Why did this happen?.

Thanks, Dave  

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if the die nut is pitched you can cut a real wonky thread that runs well off line to the original , hence it machines off metal you needed to ...keep 

all std threads would be 5/16" x 24 tpi unf    threads in alloy woul have less TPI and a coarse pitch 

all 1/4   5/16   3/8  dia UNF std threads have a tpi of 24 

pete

 

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I don't use dies very often but the cheap ones I have (a Halfords set) do tend to undercut rather badly. To be honest, if I think a stud is looking past its best then I usually just replace it. Re-cutting male threads is reserved for things like the rear shocker attachment where the "bolt" is a welded in part of the assembly.

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45 minutes ago, clive said:

It may be better to use a thread chaser, bit more gentle and tend to reform the thread rather than cut.

A few years ago now I asked the father-in-law to help refurbish the threads on a Herald petrol tank drain plug, as I didn't have anything to fit that thread or size. After hours of very careful measurement and gauging he set it to one side, and when I called back later in the week it was still untouched. He put it in the lathe, took a thread chaser, and spun the lathe whereupon massive quantities of metal came off leaving it almost smooth...  then asked: "Is that okay?"

After leaving me to debate my reply for a few minutes he then produced two brand new ones that he'd machined for me. 

However: re dies - they're really just for cleaning and realigning threads, not recutting; I always reckon that if they're removing metal they're weakening the grip of the threads. As Rob says, where the threads are part of a larger component they're worth dressing and cleaning, but if it's only a stud and it's worn or corroded then replace for peace of mind.

 

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and  Hand use of taps and dies varies,  all need  decent lubrication oil or grease , wd is cats pee not really  suitable .

first taught method

half a turn on and and back off, this is to break the swarf but can trap it and snag going forward making progress lumpy

last taught

  is continuous turns no backing off , plenty of lubricant 

take your pick 

Pete

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I needed to repair the thread on one of my headlight cowls. Being alloy it had stripped somewhere along the line and, of course, the retaining bolt had fallen out. I got hold of a couple of metric rivnuts (couldn't find any imperial) and managed to re-cut the thread on one to imperial fairly successfully. I just need drill out the hole if there is enough metal, and fit it, but that's a job for over the winter along with all the others.

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https://www.machinemart.co.uk/p/cht302-24-pce-tap-die-set/

This is very close in spec to the set I bought from Machine Mart in Carlisle back in the 1990s (on the way home from Stafford!)

It's lasted well, almost 30 years now, cost me about £20 back then and fits all of the studs and bolts on my Triumph.

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That's the one I have. The stud I used it on was only a bit scuffed lower down, though still found it hard to get it to track cleanly.

Will do some practice

I assumed to secure the dies, you screw down the top screw a bit til it bites to spread it, then then the two side ones to secure it.

Ta  

Edited by daverclasper
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When 'cleaning' a scuffed stud (Pax, Pete), I screw that spreading screw in until i can get the die to spin on loosely, then slowly bring it back tighter, until I'm satisfied with the cleaned thread, by running a nut up and own it.

The problem for something like the manifold studs is that there's no space to swing the die holder.   That's when a die nut is useful,   They are thread chasers for cleaning up threads, not cutting them in the first place, and so less likely to remove excess metal.   They may, of course, be driven with a socket set, making access easy.

M2 x 0.4 HSS Hexagon Die Nut Metric Course. Threading/Hex Shank Hexagonal  (M2 x 0.4 (2mm)): Amazon.co.uk: DIY & Tools

Even better, if you don't have any die nut, you can make your own from any nut that fits the thread.   Cut a slot into the nut's  internal thread with a hacksaw, or a triangular file.   Clean it  by running up and down a spare bolt, and then use it like a die on the damaged stud.    One home made die nut will last many studs!

JOhn

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35 minutes ago, JohnD said:

Even better, if you don't have any die nut, you can make your own from any nut that fits the thread.   Cut a slot into the nut's  internal thread with a hacksaw, or a triangular file.   Clean it  by running up and down a spare bolt, and then use it like a die on the damaged stud.

Have done that a few times! It's quick and effective for cleaning up threads but only if they're not too far gone.

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Colin I brought my cheap Jap Tap and Die set probably 40 plus years ago there still in the same case with instructions and maybe the 3/8 UNF tap n die are original but the rest are like an woodcutters axe how many new handles and heads have there been in that 45 years!

Question for those mech minded which are better split or star anti shake washers? On alloy I prefer star, 

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7 hours ago, Peter Truman said:

Colin I brought my cheap Jap Tap and Die set probably 40 plus years ago there still in the same case with instructions and maybe the 3/8 UNF tap n die are original but the rest are like an woodcutters axe how many new handles and heads have there been in that 45 years!

Question for those mech minded which are better split or star anti shake washers? On alloy I prefer star, 

I thought star washers were meant to put under a bolthead (or nut I suppose) to stop it turning as it is done up? Often supplied with towbars as one side is usually inaccessable to large spanners etc. 

I am not convinced split washers are that effective either. If concerned, a dab of threadlock is used. That does solve the problem right up until it needs to be undone. 

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14 hours ago, JohnD said:

 

The problem for something like the manifold studs is that there's no space to swing the die holder.   That's when a die nut is useful,   They are thread chasers for cleaning up threads, not cutting them in the first place, and so less likely to remove excess metal.   They may, of course, be driven with a socket set, making access easy.

Have used a split die in tight spaces by putting a jubilee type clip around it to give you a better grip, you can also use a slot screwdriver in the split.

Regards

Paul

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15 hours ago, JohnD said:

 

M2 x 0.4 HSS Hexagon Die Nut Metric Course. Threading/Hex Shank Hexagonal  (M2 x 0.4 (2mm)): Amazon.co.uk: DIY & Tools

Even better, if you don't have any die nut, you can make your own from any nut that fits the thread.   Cut a slot into the nut's  internal thread with a hacksaw, or a triangular file.   Clean it  by running up and down a spare bolt, and then use it like a die on the damaged stud.    One home made die nut will last many studs!

JOhn

Any recommendations for supplier or brand, John? I've been lamenting tight spaces where my die holder won't turn, and those would be perfect, if I can source Imperial and preferably a small set. I've just had a quick search and all I can find are individual nuts (Goliath brand) at over £30 per nut!

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4 minutes ago, Colin Lindsay said:

Any recommendations for supplier or brand, John? I've been lamenting tight spaces where my die holder won't turn, and those would be perfect, if I can source Imperial.

I always buy taps& dies from Tracy Tools https://www.tracytools.com/ but I've just looked and they offer no dienuts at all!   So I'm at a bit of a loss, sorry!     But as said, a home made one will serve in most situations where a new stud isn't essential.

 

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eBay seems to have a thing about "die nut"!

I just had a look, while I had a late lunch, and the top items were a dozen icons and German/Dutch 'genre' paintings!     I can undrstand why "die" might confuse its parser and send it Germanywards, but how does 'nut' spell 'icon'?!

Anyway at the cheaper end (5K Euros  for an icon!) lots of die nuts:  https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=die+nut+-M&_sacat=0&LH_TitleDesc=0&_sop=15&_osacat=0&_odkw=die+nut

John

PS Ah!   Search for 'dienut' and eBay stays away from the art market!

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