Whitworth sets for dummies?

[cody6268]

Been meaning to get me a Mamod steam-powered traction engine to mess with, and apparently (and especially with vintage examples) it uses BA/Whitworth bolts/nuts to hold itself together. From both here, and being a fan of British automobiles (esp. Land Rovers), I"m familiar to an extent with Whitworth, but not really that much; basically I just know it exists.  What I'm seeing sold for use with Mamod looks like bargain-bin special junk. 

Do any Whitworth sizes coincide with Metric and SAE? I do have lots of those; including a whole set of super-tiny SAE wrenches from Craftsman.  Any decent small wrench/socket sets that don't cost a kidney?

[Papaw]

Whitworth has a different thread pitch , but as for wrenches, other will fit, just won't be what you are used to. Whitworth wrenches are usually marked with sizes relating to the shaft size of the fasteners.

[Bill Houghton]

Whitworth has a different thread pitch , but as for wrenches, other will fit, just won't be what you are used to. Whitworth wrenches are usually marked with sizes relating to the shaft size of the fasteners.

And, strangely, the head sizes on the fasteners will differ for a given diameter of bolt/capscrew depending on whether the thread pitch is coarse or fine.

Whitworth has, also, a different thread profile.  Some argue that it's a superior profile, but the battle got lost years ago.

[oldgoaly]

If my memory serves me right Whitworth is 55* thread pitch, having a prewar MG you can find all kinds of bolts and nuts. War time "unified" came into play.

[amecks]

I'm not entirely familiar with BA sizes.  There's only a few spots on a British motorcycle that use BA threads.  You may do OK using a good set of ignition wrenches that has sizes in the 64ths range.  If you need fasteners I would recommend British Tools and Fasteners.  For small orders call Jon, he will send via first class mail, saving on shipping.
https://britishfasteners.com/