[DerAlte]

Originally Posted by aargee

If I understood right, breaks the spanner? ...

Yes. Though I have never managed to break one, I have had occasions where the spanner started straight, and ended up with the head at an angle to the shaft (had used a pipe to get more torque), but the head didn't snap off.

Originally Posted by aargee

... octangon shape of the bolt to round ...

Yes. Not an octagon - bolt-heads and nuts are almost always hexagonal. If it was an octagon, there would be more chance of it becoming round.

[Thad E Ginathom]

I've bent simple stamped-sheet pliers, but with a proper spanner, the head sheers off the bolt before the spanner breaks!

[aargee]

@DerAlte sir - Now this is about the smooth transitioning that you've explained on the spanner to crack/break. But I'm under the impression that this is the basic engineering work that is done on any spanner when manufacturing isn't it? If that's the case, why do we see so many models?

If you look at 3 & 5, they're of different finishing all together, while I sense some similarity in 1 & 4 & 2 being the odd man. What I do not understand is the basic engineering is the same, may be 2 is having a little more strength while all others are of almost the same type. Why make them at all? Is it just for the cosmetics? I'm sorry that I couldn't get this into my head.

Edit - Thanks for the correction on the hexagonal nuts; though I've been working on it several years now, never bothered to count the number of sides.

[anku94]

Originally Posted by Thad E Ginathom

I still have some small handtools,..........

.......even though she had been in the real pro trade for years!

That is so AWESOME !!

Originally Posted by Thad E Ginathom

(left me with a still-unfulfilled desire to own a lathe!)

I've always (I mean, since the last year or so) wanted a lathe. To make chess pieces ! It was something inspired from a video of a potter making a pot. The simplicity of using rotation to make smooth curves amazed me. Although, I like metal and glass more than any other material.

Let's shut up now before the mods swing their axe. I've already got a 7-point infraction.

[Thad E Ginathom]

I go the yearly engineering exhibition at the Chennai Trade Centre.

One of these days I'm going to come with lathe, milling machine, grinder ...

[SPIKE ARRESTOR]

Originally Posted by aargee

Attachment 388018
I used to always wonder why there're different finishing in the wrenches. Is it only the quality? If that is the case, then why do even manufacturer such as Craftsman make different finishing? Can anyone help understand pls?

Aargee, AFAIK the portion highlighted by you does not have much significance, only thing that must be ensured is that the curves are not abrupt otherwise it will lead to stress concentration resulting in failures during tightening. The spanner head (the region which contacts the bolt,nut head) has fixed proportions as per IS/JIS standards, they are not played around with.

The only thing that I can think of is:- The tool makers use forgings from different sub-vendors who may have different manufacturing processes hence resulting in varied shapes.

Spike

[DerAlte]

Originally Posted by aargee

... why do we see so many models?
... Why make them at all? Is it just for the cosmetics? I'm sorry that I couldn't get this into my head. ...

Very valid question, since the manufacturer seems to be the same. The key parameter in the variation is selling cost - quite likely the fine differences between the models would be have a bearing on price. I would think No. 5 is the cheapest, and No. 2 is the costliest.

The cheapest would be intended for light-duty usage, and though unpublished would have the least torque handling capability. It would be cheapest because it would have been forged in one go, chrome-plated and sold. The cost of the die used in forging would have been the least, it uses the least metal in all the 5, and quite likely it wouldn't have been heat-treated to prepare the material for stress.

The costliest would be intended for professional heavy-duty usage, and would have a much higher torque handling capability. There is more metal in this one, would have been better heat-treated, and the die used for forging this one would be much costlier. Also, this would have been made in a multi-step process. All that adds up to cost before it leaves the manufacturer.

All 5 will do the job in normal circumstances, but the difference will be in "Oh, shoot" and "There you go!" in tough situations. Those whose daily bread is dependent on tools would prefer to be in the 2nd scenario. Though the old adage "a bad workman quarrels with his tools" seems to say otherwise, good tools make a LOT of difference in doing a job well. It is easy to make out how professional or otherwise a person is based on how they relate to their tools.

Originally Posted by SPIKE ARRESTOR

... The spanner head (the region which contacts the bolt,nut head) has fixed proportions as per IS/JIS standards, they are not played around with. ...

Not really. IS / JIS specifies the minimum required to be compliant with a standard. One need not, the product will still sell to people who really don't care. Such country-specific or international standards bodies try to maintain minimum standards of quality of products in the interest of consumers. There is nothing to say that those minimum standards cannot be exceeded, and many manufacturers do that by making genuinely much-better-than-minimum-standard products.
In the case of the spanner, there is a minimum head thickness specified apart from the dimension of the opening (like 12mm, not 11.5 or 12.5). The head thickness dictates the probability of the spanner spoiling the nut/bolt-head (stripping, cutting). IS specifies the minimum, but if a manufacturer exceeds that in the interest of preventing stripping at higher forces (as also being able to exert more force on the side of the nut/bolt-head), they are free to do that and still be IS/JIS compliant.

[anku94]

Originally Posted by Thad E Ginathom

I go the yearly engineering exhibition at the Chennai Trade Centre.

One of these days I'm going to come with lathe, milling machine, grinder ...

Here's something. I love it.

English Russia Russian Wall-E Case Mod

[Thad E Ginathom]

Nice. I wouldn't have a clue about most of those processes!

[anku94]

You wouldn't ? Is making one like that that difficult ?

[Thad E Ginathom]

The only metal-working power tool I have used since a brief go on the lathe at school is a bench drill (yes, I used to be able to sharpen drill bits, but not very expertly!) --- when I was doing semi-skilled factory work. I'd guess that the first thing I'd do on a lathe now is break the point off the tool! Milling machines and surface grinders are possibly even more "awesome" than lathes, but I'd have to go back to school to learn their use.

Another of my favourite tools in the jewellery workshop (corner of my bedroom for a couple of years) was my polishing motor. Actually a very dangerous thing to use: if you don't hold the piece right, the fast-spinning mop can grab it out of your hand and project it at high speed. If you're lucky, it misses you and gets smashed against the wall. Polishing chain, if you don't hold it the right way, can cost fingers.

I wish I had one now for the brass in the house, although I don't know what compound to use.

[DerAlte]

There are buffing compounds available at industrial supply stores - sort of large crayons with very fine abrasives. One is supposed to use a cloth wheel - the compound sticks to the cloth edge. Ask at any neighborhood shop making plastic signage - they will know where it is available.

At a pinch you can use Brasso on the wheel.

[Thad E Ginathom]

Unfortunately I don't have the motor any longer.

Might invest in one, one day, though

Used to use two compounds (strictly separate mops) for silver/gold; tripoli, a cutting compound, to remove the finest of scratches left by the finest of sandpaper (called crocus, if I remember) and rouge, which is burnishing compound for the big shine.

It probably wouldn't take much nosing around Parry's to find this stuff in Chennai: there must be guys there that supply to the jewellery trade.

[anku94]

Originally Posted by Thad E Ginathom

The only metal-working power tool I have used since a brief go on the lathe at school is a bench drill (yes, I used to be able to sharpen drill bits, but not very expertly!) --- when I was doing semi-skilled factory work. I'd guess that the first thing I'd do on a lathe now is break the point off the tool! Milling machines and surface grinders are possibly even more "awesome" than lathes, but I'd have to go back to school to learn their use.

Wow, maybe they'll teach us all this stuff at the Metal Workshop when I get to college. I'm dead clumsy, though. :(

[aargee]

@Deralte Sir, Bingo!!! the keyword is "usage" is what hit the nail. I agree completely, one should go based on the usage. Thank you very much for helping me understand; now next time when I go buying one, I'm sure to review your post & hit the market; I'll buy things based on my needs.

I'm looking for buying a hand tool, that is something like this to serve the following purpose by simply changing the blades
1. Cut wall, glad if it could cut concrete
2. Cut metals such as iron/alumunium, wood & water pipes (both Gi & Pvc)
3. Additionally extend to polish car like this

I don't want a heavy dutier, but a medium one for house hold purpose to aid in plumbing & light motorcycle work.

My questions are...
1. First of all, is my list valid? I mean, can I accomplish the multiple cutting jobs by simply changing the blades & without varying the RPM's or the machine? More simpler words, does one machine fit to do all the jobs?
2. Can I simply replace the blade with a buff & extend to polish the car? Is there such a model available?
3. I intend to buy Bosch, any additional information is highly appreciated on how to look for a ideal machine. Thanks.