What type of steel

[richiegallon]

Hi everyone, I'm after a bit of help please, I'm hoping to go on an MOT testers course soon but although I've worked in the motor trade for years I don't have the relevant qualifications to take the course so I have to take an exam before I go on the course, it's a sixty question multiple choice exam called the NTTA test. Anyway, I've seen plenty of mock question etc online but there are two that I'm having a bit of trouble with, so I thought I'd ask you knowledgable people!
The first question relates to the construction of modern vehicle body shells,

Which metal is used in the construction?

A. Mild steel
B. very low carbon steel ( 0.1% )
C. Relatively low carbon steel ( .15 - .25% )
D. Spring steel ( pretty sure its not this one! )

And the other question is

Which roller bearings are subjected to greater radial but no axial loads

A. Single row ball race bearings
B. cylindrical roller bearings
C. Taper roller bearing
D. Double taper roller bearings

Any help would be much appreciated guys, thanks in advance!!

 

[jay1800si]

hi. I took that test a few years ago. I would recommend reading plenty about steering and suspension geometry as there were quite a few questions about that. car bodyshells are made from mild steel. I haven't got a clue about the bearing!

 

[FranV8]

Bearing is answer B. The rollingeelements are all plain parallel cylinders, if loaded axially the races would just slide along.

 

[adamsmitqc]

Cylindrical roller bearings are designed to accept radial loads only.

Single row ball bearings accept both radial and axial loads and any type of taper roller bearing will accept both radial and axial loads. Often seen where there are severe axial loads (thrust bearings and I'm pretty sure the last front wheel bearing I changed on a Volvo was a taper roller)

 

[ronan]

I concur , mild steel and cylindrical roller bearings.

 

[rikrobson]

Mild steel is a low carbon steel and covers a range that would include the other two low carbon options!!!!

Bit of a poor question. the lower the carbon content the easier it is to make panels out of. I think they are looking for relatively low carbon steel as the answer

 

[ronan]

Mild steel is a low carbon steel and covers a range that would include the other two low carbon options!!!!

Bit of a poor question. the lower the carbon content the easier it is to make panels out of. I think they are looking for relatively low carbon steel as the answer

You are right of course rik, the second question could also be a trick , it says "which roller bearings are subjected to greater radial but no axial loads", which to me says more about the loads applied rather than the bearings themselves. A cylindrical roller bearing may have an axial load applied, it just won't last long.

 

[Drains]

The first is a rubbish question and not answerable IMO - both mild steel and (their definition of) relatively low carbon steel are virtually the same thing. More to the point, many body shells are constructed from boron steel - hence the whole braze welding thing required to repair modern cars. If it were a written multiple choice you could write all that (I would), but as it's probably computer based, god knows what they think the right answer is.
I don't think either question is a trick - they don't do that on this kind of test - it's very bad practise indeed. The second one is straightforward.

 

[octo0072000]

have a look on the mot forum

http://motforum.proboards.com/thread/99/ntta-exam

 

[Hitch]

They use all different types of steel to build cars.....


Heres a bit about Volvos, with a nicely colour coded diagrams to show the different strength steels and where they are used.


http://boronextrication.com/tag/volvo/

 

[rikrobson]

of course there are other materials used in car bodies ,such as, plastic, GRP and aluminium alloys. Not forgetting wood too, but not on modern cars.

 

[500e]

They still make Morgan's

 

[octo0072000]

They still make Morgan's

out of wood frames

 

[Wedg1e]

The second question's poorly phrased as it asks 'Which ROLLER bearing...' but answer (a) is a single row BALL...

 

[richiegallon]

Hi lads, I just wanted to say a big thanks to all of you for your input, I took the test this morning and passed with 92%! I'm very pleased with that! Neither of those questions came up tho!!

 

[octo0072000]

Hi lads, I just wanted to say a big thanks to all of you for your input, I took the test this morning and passed with 92%! I'm very pleased with that! Neither of those questions came up tho!!

that's the first bit done all you have to do now is the practical
well done on the theory test
been there done that had the tee shirt hated it too many common sense things that should be a fail is still a pass and advise

have fun

 

[richiegallon]

that's the first bit done all you have to do now is the practical
well done on the theory test
been there done that had the tee shirt hated it too many common sense things that should be a fail is still a pass and advise

have fun

Cheers!!