Hello all

If you want to see metric to imperial equivelants buy a Zeus book. It shows tapping and clearance drill sizes for metric and all imperial threads, Whitworth, UNF UNC and BA as well as other useful technical data (i.e. bending radii for when you are making sheet panels, imperial and american gauge sizes etc) The book is pocket size and wipe clean. Very useful (all "engineers" should have one)

Google Zeus Book to find a supplier or try RS components


Sorry to those i'm teaching to suck eggs

BSW (British Standard Whitworth) and BSF (BS Fine)spanners are labelled by the thread size and are not the across flats (AF) size. If I remember correctly each spanner end would have both a BSW and BSF thread size shown.

BA threads was used mainly for electrical equipment and very small intricate work (watches for instance) The spanner is marked as per the thread size and range from 0BA (The largest) to 20BA (the smallest) RMS use mainly 2BA for electrical panel screws (which is why you cannot get a metric screw in).

UNC and UNF (Unified course and fine) spanners use the across flats (of the bolt head)

Thread-Spanner
3/16 - 3/8
1/4 - 7/16
5/16 - 1/2
3/8 - 9/16
7/16 - 5/8
1/2 - 3/4
9/16 - 1
3/4 - 1 1/8

Metric spanners are also measured across flats i.e the thread and across flats size are different.

Thread Spanner
4 - 7
5 - 8
6 - 10
7 - 11
8 - 13
10 - 17
12 - 19
14 - 22
16 - 24
20 - 30

These AF sizes are typical for standard nuts and bolts but may differ on special parts.

As an electrical apprentice I learned the above as well as how to sharpen drills, the difference between pozidrive and phillips (They are very different and if you mix them you WILL ruin both your screwdriver and screw head) and to make sure a flat head screwdriver fills the slot on the screw or again damage will occur. All tools should be cleaned after use.

They teach apprentices bugger all now.

Bloody hell I sound old

David Colin

Try the CLERKENWELL SCREW COMPANY if they're still there

they specalise in engineering fixings etc.

Claire

Hi Colin

No, you don't sound old.

Time served to a yougster these days means time spent in the slammer.

Time served to our generation means someone who had been trained to a very high standard.

One of the things I did at Aquila (MOD) Bromley was to make a spanner for a nut. Sounds simple but it is really difficult.

There was a bloke there who spent a year of lunch hours filing the wheels for a live steam loco out of solid steel blanks.

Happy days!

J

No lathe then Quite a task without a lathe and a mill

Claire

When I started my training in the electronics industry it took me 4 long years to get that knowledge , now its just the ' throw away ' era . When I joined BT as an external faults & cable engineer I , like all the rest at the time , spent 3 WEEKS just learning & being taught how to join cables together correctly .. today they spend 4 DAYS , are given a van + one piece of test equipment and are then let loose on the network ... we on the other hand spent at least 4 MONTHS with an experienced engineer before being let loose . I'm not against change BUT it needs time to learn to ' do it right ' ... perhaps thats why the Iconic Routemasters have lasted so long -- just a thought ..