I have a Bialaddin 300X with one nut of the handle that does not want to turn outside at one point, making removing the top a matter of painful fingers. Someone before me has used some pliers already on the tender serrations, but none too damaging so it does not need replacement. When disassembled in a vice with leather clad pliers, the thread on the brass bolt of the frame is damaged to shiny brass. Soaking in acetone of the nut does not make for any relieve, so something is wrong with the female thread of the nut. The screws that secure the frame to the tank are no match in the end (slightly smaller diameter and finer thread). I want to run a tap through, but I have no idea of which size this would be. Does anyone know? Mike
I'll have a check tonight but I suspect it'll be 2BA. The screws that fasten the collar onto the fount are 2BA so if you try one of those in the bail nut that'll tell you. Has anyone else got any idea?
Colin, such a screw does seem to fit, but too loose. The threadsize on the frame is slightly bigger in diameter. As a consequence, such a screw I can push inward in this often forced frame nut, while it will thread inside its mate on the other side. I am dyslexic where it concerns reading inches on the callipers, but in millimeters it is 4.60 and 5.35 respectively and measured with several screws and frames. The ghost of Matchless and Norton motorcycles with their quirky threadsizes is looming again. Mike
Measuring mine with a thread gauge they have a 60 degree thread with a pitch of 0.9 mm. Best match given this and the outside diameter is a #12 UNF thread .
Measuring one here I get 28 tpi exact with dia .21" or 5.22mm (vernier) It doesn't match 2 BA tap or die or BSF . Will look further when I have time. This might help http://www.metricmcc.com/catalog/Ch10/10-1012.pdf
Here you go... UNC and UNF - Unified Inch Screw Threads 28 tpi 0.21" is #12 UNF. Apparently in the 1940's a lot of British companies started using UNC/UNF instead of BSW/BSF.
Steerpike and Graham - and Colin, many thanks for your help! The suggested #12 UNF seems to be right. Now I can look for such a tap, likely more expensive than a complete handle but I prefer to repair rather than replace. Again, thank you very much! Mike
So which thread seems most damaged? The male thread boss on the frame or the female thread on the knurled bail nut? I ask because I can send you a couple of bail nuts if that helps. I'll even polish them up a bit if you like! Thy're not too hard to get back into the bail if you use a vise and a pair of chunky pliers to twist the loop to one side.
Colin, How kind of you to offer this assistance! I am not in such dire straits however, even if parts this little away from Britain are hard to find. I will seek that tap to clean up the inner thread of this obnoxious nut, not out of need but as a matter of wanting to do it this way. Again, thank you for this generous gesture. Mike
While we are in a thread about threads this may be of use :-https://www.gewinde-normen.de/en/12-un-thread.html it lists dozens of thread standards imperial & metric
Incidents like a hard to turn bail nut lead to above inquiry. Then, typically for me at least, it disappears to the background, but still simmering. Recently I got to delve in a stash of Smiths speedometers and Lucas magneto's and focus came on BA (British Association) kind of threads. With a remark by Colin about a BA size vagely in memory, I managed to get my hands on a set of BA taps and dies, and hey presto, size No.1 does seem to fit. A first tap of same size then served to chase the thread of the offending nut.... that produced some fresh brass and debris ... enough to make the nut to thread on the male boss with little effort as it was intended to do. Job done, with again thanks to your various input! Mike
Glad you had a satisfactory outcome and now we have another useful specification for future reference. I am still searching for the thread size used on the screws that hold early Bialaddin frames together... specifically how the frame rods are fastened at the top and bottom.
I just removed one of those screws and found it fits like a glove in the No.5 die. It seems BA was the go-to thread for anything more refined in the fields of mechanical and electric. While I was lucky to get a classic set from Ebay, complete and let in a massive beech box, you should have no problem finding some taps and dies on the 'bay. It is still popular with the model-making crowd and I suspect the last 320 made in Halifax had identical specifications with the bail. The Koreans might have changed that, but perhaps kept the tradition just to be 'different'! Mike
Excellent, thanks for the information. I might look for a set of BA taps and dies as they will definitely be useful for repairing anything made by Willis & Bates.
I confess to being a tool nut. But I decided to buy this BA set as I do have work for it with some vintage magneto ignitions as well. The trouble with the bail nut must rate as an odd thing, and I suppose it is cheaper, if not simpler, to replace anything with the W&B lamps if you live in Britain. But good luck with your project(s)!
The gallery spring retaining nuts for Tilley are 4BA and I think the same on the radiator reflectoruts. ::Neil::
No, they are branded Triangle, another brand from the past. Made by the British Tap & Die Co. Ltd of Edmonton, London. They also marketed under the name Stronghold. I had already a box with Withworth sizes, and I like their quality.
