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Member postings for SillyOldDuffer

Here is a list of all the postings SillyOldDuffer has made in our forums. Click on a thread name to jump to the thread.

Thread: Childhood diseases
23/05/2019 19:47:22
Posted by Samsaranda on 23/05/2019 19:17:33:

I see that according to Silly Old Dufffer the state should have stamped on me many years ago for my stand on my children’s well-being, sorry to disappoint still alive and well, well I was the last time I checked and my three children made it through life successfully. 😇.

Dave W

Which is why you have to beware of individuals with quick easy answers to difficult questions. They could be idiots! I was never in your position and of course you did the right thing.

embarrassed

Time to change my policy slightly. Parents shall only be stamped on in the absence of contra-indications.

As the greatest leader Britain has never had, it's possible I was poorly advised. Not a problem though, the orphans of any parents I'd already had executed would have been sent a bunch of flowers...

Dave

Thread: DraftSight no longer free
23/05/2019 19:09:09

Hi Andy,

I (and a fair few others) use QCAD which is LibreCAD's older brother. QCAD also has a free community edition, plus a commercial version (about £30), that adds some worthwhile features. All three of them are competent 2D engineering drawing packages. QCAD is actively maintained. LibreCAD looks stalled at the moment: I couldn't download the latest stable version and the PPA site says it hasn't been updated for 166 weeks. That said, version 2.1.2 in the Ubuntu Repository looks in good shape. QCAD is my go-to tool for drawing single engineering objects, scale plans, templates etc - anything from back of an envelope to proper projection drawings with layers, dimensions, hatching and a version number! Simpler and easier to learn than Autosketch, which has too many unrelated bells and whistles for me.

I also use Fusion 360 which is a much more powerful 3D CAD tool. It comes into it's own for complex objects and especially Assemblies. For example, Fusion lets you model the individual parts of a machine and then model them together with approprate joints such that the machine can be animated. You can see if moving parts are going to collide without making a real one. Fusion can also produce rotatable photo realistic images, do stress analysis, produce 2D drawings, and output CAM instructions.

Although I find Fusion fairly intuitive, 3D CAD can be a steep learning curve, and the package has multiple capabilities. Getting to grips with it is a hefty investment of time and energy and you might have better things to do. MEW is running a course on Alibre at the moment; also very capable and well worth a look, but Alibre will eventually cost money.

Of concern is that Autodesk might change their minds about the free licence currently on offer. Draftsight was free for a long time before users got that nasty message. A pessimist might expect Autodesk to pull the same trick - get you hooked, and then demand money. For that reason I also keep up-to-date with FreeCAD, it's more obviously in development and whilst not in the same league as Fusion & Co functionally, it's genuinely free. An optimist might think Fusion a good bet because Autodesk are implementing a clever long term strategy: they don't intend ever charging hobbyists and students, the plan is to put loads of self-trained Fusion people on the job market, such that employers switch to Fusion to reduce their eye-watering training costs.

To keep life simple, it might make sense to choose the minimum the part-cutter will put up with. If he only needs properly scaled 2D plan drawings, LibreCAD/QCAD is easier to learn than Fusion.

Producing good engineering drawings can be quite hard; there are do's and don'ts. A basic book might help get you started.

Dave

 

 

 

 

 

 

Edited By SillyOldDuffer on 23/05/2019 19:11:21

Thread: Beginners question (sorry) - why I am breaking my small centre drills?
23/05/2019 17:57:28

A few more possibilities:

  • Small centre drills are rather weak and you're heavy handed. (I break them fairly often.)
  • The centre drill is too cheap...
  • The tailstock is off-centre. Drilling off centre causing it to bore, cutting on one side rather than drilling. Usually fairly obvious when the tip first makes contact, but the other give away is the drill cutting an over-sized hole.
  • It's one of those days. (I bored a cylinder exactly 0.1mm too big this afternoon.)

Dave

Thread: Childhood diseases
23/05/2019 17:44:26
Posted by Neil Wyatt on 23/05/2019 16:58:17:

...

It's the aversion to dirt and obsessive cleaning that ... is possibly behind the increase in auto-immune conditions like asthma, eczema, coeliac disease, nut and many other allergies.

Neil

Phew! I'm safe then. Been compared to a goat down a coal mine I have...

Thread: Fire bricks
23/05/2019 16:13:21

Firebrick is one of those words with two contradictory meanings. There's the type that absorbs heat, and the type that doesn't. What fun the confusion has caused in this thread!

Can anyone think of other examples? For example, bollocks is bad, but the dog's bollocks are good. And I might say of a too hot to touch loco belching steam and smoke, 'gosh that's cool'.

Is there a linguistic name for words that contradict themselves?

Dave

Thread: Childhood diseases
23/05/2019 13:12:05

The problem with achieving 'natural immunity' is developing it requires you to catch the disease. Measles, mumps, and chick-pox are mostly mildish illnesses, but they can all turn nasty. Killers. Not unusual for measles to cause blindness or even death. Grown men fear mumps for good reason - it causes agonising swelling of the testes and sterilisation.

The advantage of artificially immunising against disease is that vaccines are much less aggressive than wild bugs. As soon as they became available, most countries used them and real outbreaks all but disappeared. Denied of hosts Smallpox has been eliminated entirely, but not the others. Sadly, because vaccines are not completely safe, and one has been falsely linked to autism, many parents have chosen not to vaccinate their children, and as a result, the real diseases are back. (In my opinion objecting to vaccination is so stupid the state should stamp on the parents. Selfishly refusing vaccination endangers the population as a whole - people risking their own kids is one thing, but in my view it's not acceptable for other children to suffer because of misplaced parental concerns. )

Before 1950 contagious diseases were common, and they were rampant before 1930. Measles killed 1,145 children in 1941 Britain, between the years 2000 - 2016 only 1, 2 or zero per year. I'm lucky to be here because my mum, aged 4, only just survived Diphtheria.

Immunity provided by vaccination is at least as good as naturally acquired immunity, applied consistently it protects everybody, and it's far less dangerous.

Dave

 

 

 

Edited By SillyOldDuffer on 23/05/2019 13:12:33

Edited By SillyOldDuffer on 23/05/2019 13:15:09

Thread: Interesting??
23/05/2019 12:09:31
Posted by Phil Whitley on 23/05/2019 09:13:00:
Posted by SillyOldDuffer on 20/05/2019 21:07:05:
Posted by Phil Whitley on 20/05/2019 20:07:54:

... Science and scientists have a very poor record of invention of anything in common use today. ...

A very unfair criticism of science because the goal of science is understanding, not inventing! It's other people, like engineers, who exploit scientific understanding by inventing new things or improving old ones.

Dave

I don't see it as unfair, pointedly accurate perhaps, science is often understanding for the personal satisfaction of the curiosity of an elite, who never put that understanding into practical use. ...

Our entire electrical system was brought to the point it is in today by a small group of brilliant engineers, Tesla, Heavyside, Maxwell and Steinmetz are the main ones, and their work has been advanced very little in the years since their passing, and also no one ever heard of them, except perhaps Tesla. Einstien on the other hand is universally known, and much of his work is theoretical and obscure (and possibly wrong, they are only theories!), he got his Nobel prize for a paper on the Photoelectric effect, which he neither discovered or put to use, he merely "quantified" it.

Gosh Phil, we must agree to disagree. That seems a warped view of science and scientists to me! It's a dangerous view too, because our economy can't exist without scientific method. It's fire the goalkeeper because he never scores and he lets a few in.

Einstein is a good example. At the end of the 19th century most scientists thought a complete understanding of Physics was in sight. It appeared that Mechanics, Thermodynamics, Magnetism and Electricity were nearly complete with nothing else to study. Only a few anomalies like black body radiation, why the sun is hot, and the photoelectric effect needed to tidied up. As it turned out, these are doorways to new vistas of investigation and studying them made 'High Technology'. Semi-conductors rather than Steam Hammers.

I suppose Einstein's paper on photoelectricity could be written off as elitist, but the work ignited Quantum Mechanics, without which - for instance - GPS wouldn't work. Another theory - Relativity - led to an entirely different insight without which GPS wouldn't work either, and to the potential of Nuclear Weapons. He discovered new worlds of thought and the extent of his genius is 100 years later most people, including me, are incapable of grasping all the concepts.

Einstein got the Nobel Prize for Photoelectricity because his theory of 1905 was confirmed experimentally in 1914. (Experimental confirmation of theory was essential before a Nobel Prize would be avoided.) His other work is much harder to prove experimentally, and although parts have been confirmed in the real-world, it remains a Theory. Einstein was not satisfied the theory is complete or necessarily correct, but so far, with modifications, it's holding up. But, like 19th Century Physics, there are a few embarrassing anomalies to be explained... Failure to find an end is the nature of science, the goal is disciplined enquiry, analysis, and understanding, not making better mousetraps.

Tesla and others made Electrical Distribution practical, and it is the system we have today. But their achievement wasn't the end of the story by far; they did not deliver the internet!

Science, Mathematics, and Engineering are close relatives. When Bessemer invented his world-changing converter, joy turned to misery when customers bought expensive blast furnaces and found they made brittle crap. A job for the chemists, who discovered that the problem lay in high levels of Sulphur & Phosphorous found in some ores. (By chance Bessemer had tested with uncontaminated ore.) Once the cause was understood, chemistry quickly provided the answer by recommending a flux based on science, not guesswork.

Interestingly, not the end of quality issues with Bessemer steel. The modern process blows Oxygen rather than Air because chemists eventually found Nitrogen, normally inert, can react in tiny quantities to make mild-steel brittle. The problem was subtle, and no way could an engineer or furnace-man have fixed it.

Edison gets the credit for being the first to methodically organise scientists, technicians and mathematicians into teams working on sophisticated goals. His approach blurs the distinction between specialisations. Engineers and scientists both make extensive use of advanced maths. Engineers use scientific method and scientific facts to solve practical problems, and experimental scientists have to be good engineers.

The lone inventor is all but extinct. Individuals still have good ideas, but most easy to make inventions have already been done. (Unlikely I shall get Artificial Intelligence working on my dining table.) Instead, most R&D is done by collaborating specialists working in teams, including accountants! And when they've done the R&D, they will almost certainly need a production engineer and practical men to make it work.

Dave

Thread: sieg mill: normal chuck or collet chuck?
23/05/2019 09:40:40

Like as not you will use both. Most of the time I mill and drill with a metric ER32 collet chuck. Three main exceptions:

  1. Too often for comfort, Imperial drills aren't a natural fit to metric collets. Although Imperial collets will adjust to hold a metric drill and vice versa, it can be a faff.
  2. If the job requires many holes to be drilled in different sizes, drills can be changed faster in a drill chuck because you don't have to swap collets.
  3. The smallest ER32 collet can't grip less than 2mm, and many drill chucks can hold smaller. For very small drills, I grip a miniature drill chuck in the collet chuck.

dsc06104.jpg

With care it's possible to mill with a drilling chuck, but in my experience it's poo!

Dave

Thread: HSS or CS taps and dies
22/05/2019 10:14:36
Posted by AdrianR on 21/05/2019 19:37:30:

Hmm tapping compound, when I was at school we had a pot of tallow, and happily my father had a similar card board pot too. I have used lard in the past, but since my move all I have is neat oil.

I have seen people mention Trefolex and Rocal any other suggestions?

Regarding tapping drill size. For M6 I have two books, one says 5.6mm the other 5.3mm. I am tapping a 19mm deep hole so chose the 5.6mm to reduce the thread percentage and make tapping easier. For relatively deep holes what percentage thread would you use?

Tapping compound - always a good idea to use something! I use CT-90 because it's what my local place keeps on the shelf. The modern mixtures have somewhat better heat, pressure and lubricating properties than old-school organic recipes. They are also unlikely to be a biohazard. In the old days lard etc would rot and cause painful infections via a scratch.

For tapping drill sizes, how strong do you need the connection to be? The average bolt isn't heavily loaded, and when more strength is needed it might be easier to use a bigger one than a close fitting thread. Production tends to avoid tight threads because making them wears out tools and slows down assembly.

Most of the time I use over-size tapping holes. However, rarely - when strength or safety matters - I use the recommended tight drill. Not often because I'm not bolting wings on airliners!

I don't think the depth of the hole makes much difference to choice of tapping drill diameter. Surprisingly few threads are needed to achieve full-strength. Perhaps 4. After that, additional threads in a deep hole don't add more strength. So, it's the same decision: if maximum strength is needed, drill for tight threads and accept the tap will wear faster and is more likely to break, otherwise drill larger holes to favour the tap.

Dave

Thread: Vickers Bl 8 inch Howitzer cannon of 1917
22/05/2019 09:23:30

Seriously good work Mal. I'm admiring it in stunned silence!

Dave

Thread: Antique Steam Engine from Doorknob
22/05/2019 09:16:55
Posted by Hopper on 22/05/2019 08:22:46:
Posted by SillyOldDuffer on 20/05/2019 11:54:39:

Now there's no evidence of a coaxial crank I've gone off the idea in favour of this suggestion:

eccentricpos.jpg

I'm not convinced on this exact set-up, but rather something similar but different, for several reasons. One being that the stroke of the cross-head is significantly longer than allowed by the small crank in red. In fact it would be the same dimension as the main crank, which obviously would clang into the main crankshaft. The other being that there is no facility for the "needle" to pivot at the top, as would be required in a crank and rod type situation. The notch in the brass flange where the needle would run tends also to indicate it does not move from side to side.

I'm thinking there must have been something that allowed the "needle" to move straight up and down. So something more like a pushrod pushing a lever, in effect a rocker arm, without the two being firmly joined. Or perhaps a short crank arm as shown in red but the pushrod passing though a loose hole in the end of it, with two collars on the pushrod that allow it to move the crank arm a short distance at the end of each stroke, but slide through without moving the crank until the other end of the stroke. You thus have a lost-motion linkage in effect. So it provides a sort of "switching" motion at TDC and BDC rather than a continous cranking motion. This would be consistent with switching the valves from open to closed and vice versa at the end of each stroke, as required for a single-acting cylinder.

Just a thought.

I like it!

It's true the crank suggestion isn't convincing. A reason I suggested ornamental was because I can't imagine how a crank would communicate sensibly with whatever valve is inside. (Might be because I don't know enough about valve gear and there is a simple solution!) And ornamental doesn't fit well with the maker going to the trouble of drilling that large hole - surely it has purpose.

Hopper's suggestion of a mostly up down movement using collars to flip the valve is much better than any of my over-complicated musings. Something like the valve trip arrangement on James Watt's early engines perhaps. I'd love to know what's inside!

Dave

Thread: What Did You Do Today 2019
21/05/2019 21:20:21
Posted by mgnbuk on 21/05/2019 20:35:24:

The lead pellet weighs about 1.2 grams and would have been travelling at about 220mph on impact, about 8J of energy.

I don't think that your energy calculation is right, Dave.

Working in the more conventional units for airguns in the UK, 1.2 grammes pellet weight equates to 18.52 grains. This seems high for a .22 wadcutter. The pellet you show looks like a H & N Excite (12.82 grains) or RWS Hobby (11.9 grains) ? 220mph equates to 323 feet per second, which is round about what my recently departed Webley Tempest put .22 Hobbies over the chrono at, so seems about right..

However, 11.9 grains at 323fps works out at 2.76 ft pounds energy (3.74 Joules) - quite a bit short of 8 Joules. Even if your pellets are 18.52 grains, that is still only 4.29 ft pounds (5.82 Joules) - closer, but still no cigar. Still, you do seem to be comfortably on the right side of the law for the UK air pistol power limit of 6 ft pounds (approx. 8.13 Joules).

I don't think you should be too suprised that 3.5mm of polycarbonate stopped a pellet - I seem to recall seeing a demonstration on TV some years ago of a 1.5mm polycarbonate visor designed to clip on to a standard UK policemans helmet stopping a full power air pistol pellet at point blank range.

Nigel B (now enjoying a Weihrauch HW40 in .177)

Oh no Nigel, looks like I messed up again! I admit to not weighing the pellet, I quoted a scribble in my notebook. (From an experiment where I used an Arduino and tin foil to measure muzzle velocity.) And I have a poor record doing sums.

The pellet might be a valuable antique. It's a Milbro Caledonian, possibly bought with the pistol about 50 years ago. Seems like yesterday - how the years fly, scary.

I was pleased with the test. An obvious cost saving on a cheap lathe might be to use ordinary plastic shields, but they fitted the real thing.

Another airgun test I've not seen any figures quoted for is the real-world maximum range a pellet travels. (Not that I've done any research!) Had a notion it could be done by firing pellets at various elevations along a canal and watching for the splash. Quite hard to spot a small pellet landing when it's nearly out of energy I expect. And there's a risk the public won't appreciate my interest is science!

Dave

Thread: Cutting a worm?
21/05/2019 20:39:31
Posted by Michael Gilligan on 21/05/2019 19:04:25:
Posted by SillyOldDuffer on 21/05/2019 18:33:22:

Have you tried searching for ACME threaded rod Graham? Now that 3d printing is popular it's quite cheap in 8mm, 10mm and 12mm diameters.

.

< Pedant Alert >

ACME threaded rod is not a metric standard [whatever is advertised on ebay] ... The metric equivalent is called Trapezoidal.

MichaelG.

Gosh that burns! Good spot though - searching for 'trapezoidal' finds even more rods.

Thread: stamford show vandals
21/05/2019 20:20:12
Posted by ronan walsh on 21/05/2019 19:07:56:

People who say dire retribution does not work are misguided. A village idiot my father worked with decades ago, went to the Isle of Man for a holiday, when they still had the birch there. ...

It worked, he never dared go back there, and if he was mouthing off at work, the father would ask him if he was heading back to the IOM for a holiday anytime soon. It always shut him up.

In response to the undocumented 'a village idiot my father worked with decades ago', I offer the well known 'Mad Frankie Fraser', known as 'The Dentist' because he removed teeth with a pair of pliers.

Despite various official thrashings Mr Fraser spent 42 years in jail and was certified criminally insane 3 times. Mad Frankie said that corporal punishment made him a big man in the gangster world - it was a badge of honour like a schlager scar. Curiously, the last man to receive the Cat O'Nine Tails in Wandsworth Prison ended up in hospital after Frankie hit him with an axe (Eric Mason, another gangster). Mad Frankie finished his criminal career with an ASBO at the age of 89.

Frankie was more afraid of being sedated at Broadmoor than physical pain.

Dave

Thread: Cutting a worm?
21/05/2019 18:33:22

Have you tried searching for ACME threaded rod Graham? Now that 3d printing is popular it's quite cheap in 8mm, 10mm and 12mm diameters. Here's an 8mm on ebay, £4.19 for 300mm long. (ACME is easier to make than true square and much more common.)

Thread: Mini-Lathe setup for an absolute beginner?
21/05/2019 17:36:27

Posted by James Bennet 1 on 21/05/2019 16:38:12:

... But I read motor oil was bad due to the detergents in it?

> A cheap DIY store hand truck

You mean something like this (**LINK**), plus maybe some ratchet straps to stop it falling off?

Detergents, yes, especially in fancy modern motor oils. But they are less evident in the old-fashioned types. At the moment I'm using lawn mower oil. Mini-lathes don't use much oil, the bearings are sealed and there is no gearbox. The oil is mostly to keep the slide-ways lubricated, and to discourage rust. 3 in 1 is OK around the house but it tends to go gummy and it doesn't like heat.

The Screwfix link is to a proper stair truck, which is the posh solution. I was thinking of a cheap sack truck like this better example from Machine Mart. Mine came from a garden centre but it's OK for up to 80kg, I've seen similar in Lidl & B&Q for well under £20. Wouldn't bother with straps. The lathe is only a few inches off the floor, and if the truck was tipped enough to need straps on a stairway it would be out-of-control anyway. The important thing is to make sure no-one is ever in a position where the lathe could fall on them!

Dave

 

Edited By SillyOldDuffer on 21/05/2019 17:36:57

Thread: HSS or CS taps and dies
21/05/2019 16:42:07

Posted by Andrew Tinsley on 21/05/2019 16:11:18:

...I must just be an odd man out.

Andrew.

You're not alone Andrew, odd results and strange contradictions fill my workshop too!

blush

Dave

Thread: Mini-Lathe setup for an absolute beginner?
21/05/2019 16:22:34

I don't remember my mini-lathe being bolted to the pallet. It was in a plywood box secured with steel-tape (don't throw it away - good for shimming tools to centre-height.) I think I took the top off, checked everything was present (other boxes on the same small pallet), and then removed the sides. Not difficult, no tipping.

A cheap DIY store hand truck (£15) might help you move it, including upstairs.

No need to bolt it down they have rubber feet.

Mine only needed a light clean. It wasn't covered in the dreaded 'Chicken Fat'.

Not critical on oil, 20-30 motor oil would be cheaper & better than 3 in 1

Grease as stated, White Lithium is supposed to be plastic friendly, but I think ordinary motor grease is OK.

Tool height is adjusted by packing shims under the tool. Sorry the photo is sideways but note the bits of old coke can and other metal strip used to lift the tool on the tool-post to centre height. The angle of the ruler shows if the tool is too high or too low. It should be vertical. Reminds me I didn't have any metal strip handy when my mini-lathe arrived, and it was an annoying show-stopper.

dsc04505.jpg

I wouldn't bother checking the tail-stock alignment immediately, adjusting it is a faff! I'd start by winding the carriage and slide backwards and forwards to make sure nothing is jammed. Then turn the chuck by hand to make sure the motor and gears are free. Then stick a short length of Aluminium or Brass rod in the machine and experiment with a few gentle cuts.

Some start with a new machine by measuring and checking everything: I think looking for problems highly liable to confuse the beginner! Better to read a good book (Sparey or Wyatt), consult YouTube, ask on the Forum and do some trial cutting. Don't expect instant results. Common beginner mistakes, pussyfooting is bad because rubbing blunts tools or behaving like a demented gorilla by expecting far too much of a small machine.

The gibs and backlash might need adjustment, but I'd find out what needs fixing by using the machine. Avoid scrap. If it feels wrong or you get poor results then look for the cause or ask advice. Don't forget the operator is a potent source of trouble, and it takes time to build experience.

More fun than I'm making it sound!

Dave

21/05/2019 15:26:06

Pretty much as Thor said.

1. I am a Radio Amateur and used a mini-lathe to make antenna parts. The main restriction is the size of the lathe, notably the spindle hole. Don't expect to put threads on a scaffold pole! I agree the C0 and C1 size are too small, big is better.

2. ArcEuro are trustworthy with a good reputation, but check the specifications carefully. Mini-lathes differ at the detail level, things like the motor type (brushless best), motor power, accessories provided, carriage, steel vs plastic gears etc. Sellers sometimes drop prices so the Arc SC may be on offer.

3. Mini-lathes will turn steel, beware of random scrap, quite a lot of it isn't machinable.

4. Controller problems still pop up but they seem relatively rare these days.

5. Metric unless you have a specific reason for preferring Imperial like scale modelling Imperial prototypes, working to imperial plans, or have access to lots of imperial goodies.

6. I used Carbide mostly - for a beginner indexed carbide avoids the need to sharpen HSS.

Delivery indeed dropping a pallet at the end of the drive. Some drivers more helpful than others, but perhaps safer to assume the worst. 40kg Mini-lathes are an easy two person lift. They weigh about as much as a small woman/large child but are awkwardly balanced. I am an unfit weakling and couldn't lift mine safely from floor to bench level. (In an emergency I would have risked it, but I value my back.) Easy enough to get off the pallet and walk end by end across the floor. I used a box, workmate, and several lengths of 2x4 to raise the lathe step by step until I could slide it onto the bench. Later, a friend and I easily lifted the lathe off the bench and carried it 40 metres to plonk it in his boot. He lifted it on his own when he got home, but he's 15 years younger than me.

My machines - mostly Warco - all worked out of the box on delivery. They all needed a little fettling, but it was trivial stuff like increasing the depth of the locking hole under the High/Low lever to make it more positive, and adding a plastic strip to stop swarf getting inside the control box via the leadscrew. (Recent lathes come with a grommet.)

Dave

Edit forgot to mention noise!  Possible to listen to a radio at ordinary volume when using mine.

 

Edited By SillyOldDuffer on 21/05/2019 15:31:13

Thread: HSS or CS taps and dies
21/05/2019 14:39:40
Posted by Andrew Tinsley on 21/05/2019 12:58:48:

Interesting that most people seem to think that good CS taps are probably the best way forward. It is certainly my experience. Everyone says that CS taps are more brittle and break more easily than HSS versions. This is the exact opposite to my findings. I have never broken a CS tap, but plenty of HSS ones! I wonder why this is? If I didn't have the contrary experience, I would have surmised that CS taps were more prone to breakage.

Having said all that, I bet I get lots of CS taps breaking now. The workshop gremlins will see to that!

Andrew.

The forum likes to simplify, asking very broad questions like this one. Quite often there's a useful general answer that's not completely trustworthy.

In this example there are several types of HSS and many varieties of Carbon Steel. HSS and CS are alloy families, not individual metals that can be compared directly. Several things can be done by makers to improve the performance of Carbon Steel, and bad things can be done to HSS to reduce cost. It's a very mixed bag.

Always unwise to draw strong conclusions from a limited sample. Broadly you can expect CS to be more brittle than HSS, but it depends on what you've got. The operator is important too. Perhaps Andrew breaks HSS taps because he subconsciously expects them to be tough whilst his CS taps survive because he subconsciously fears snapping them and is more careful? Or his experience is random luck.

Most useful in this thread is the number of hobbyists confirming "Carbon Steel Taps and Dies do an acceptable job for me." It means it's probably not necessary for the average Joe to spend loads of money on the very best HSS tooling on the market. But CS getting a positive press doesn't mean buying HSS is complete waste of money either - so much depends on the job. For example, most of the time I happily thread odd holes with Carbon Steel taps. I would buy a better HSS tap if I had a lot to do and was at all worried about snapping the tap off in an awkward hole.

Dave

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