Bolt thread type?

[vhgmcbuddy]

Im trying to match some bolts. The bolt in question is from a 1950’s clifford rotavator and as you can see it has a very fine thread unlike the attempted replacement. The replacement is imperial, but has a much corser thread (plus they sent me the wrong length ones as you can see). Does anyone know what type I should be asking for (The dimensions are 5/16ths x 1 inch.) Thanks in advance.

Attachments:

1. 

[charlie]

It could be one of several possibilities, see following links for details.
BSF
BA
BSC
Is the replacement UNF?

[vhgmcbuddy]

Thanks Charlie. I knew it might be complicated, but not that complicated.
The replacements were UNC and to be honest I was just taking a stab in the dark.

What would be the easiest way to identify the one I have? Is there anywhere I could send one to to be matched? Sorry for all the questions.

[stuart]

I have some Clifford parts books which may state the thread size.What model Clifford is it and where on the machine does the screw(s) fit ??

[vhgmcbuddy]

Purchase a set of thread gauges (see pic below). I have this set which covers Whitworth and Metric threads. I also have another set for UNC/UNF. They normally cost about £5. I never enter the shed without mine!!

Attachments:

1. 

[hortiman]

Hello Ben.
I suggest you contact NAMRICK nut and bolt store, Portland Road , Hove. or just google Namrick, they have a good website, or 01273 726708. They have served me well over the years.
Chris

[mickattwo]

Where do the bolts fit?
I have a Mk 1 gearbox and a roto-box
The gearbox is very heavy and is going to the scrap man
Free for collection Sheffield

[wristpin]

A set of thread gauges PLUS a set of Roebuck ZEUS Tables will enable you to identify just about any thread. The tables are also a mine of information about drilling and tapping sizes etc

[charlie]

Benjamin the links I gave include other threads if you go to the home page. As others have said Zeus tables are a must have along with thread gauges. I have a book which details many other threads including German and Swiss variants of metric, it can be a minefield.

[wristpin]

I have posted a link to the very useful Zeus tables for identifying thread types, drilling and tapping sizes etc here is an image or two of my copy.
Sorry about the orientation but they were OK when they left here!

Attachments:

1. 
2. 
3. 

[vhgmcbuddy]

Thanks everyone – this is all most helpful and something I must begin to get my head around.
Certainly need to get a set of thread gauges and the Zeus tables
I have contacted NAMRICK (thanks hortiman) who were very helpful too.

I could have re-used the original ones, but they were such a pain to get out, that they are quite beaten up (I am changing the tine seals on my mk1 clifford).
I now have new seals, new felt washers and so hopefully with new bolts we will be back up and running with no oil leaks by spring!

I will post some pictures at a later date in case any one else needs to tackle the same job.

[charlie]

A quick google search for Zeus tables reveals that an app is now available for mobile phones.

[vhgmcbuddy]

The advice to get a thread gauges and thread guide is good advice, one Imperial and one Metric will cover any eventualities, plus in my case a Jewelers eye glass to see! It can be confusing for example the petrol tap on a Villiers engine is not 3/8″ BSF or UNF, it is in fact 1/8″ Pipe thread, thats why you need a Thread Gauge! Plonker

[vhgmcbuddy]

Yes, I am of the conclusion a thread gauge is a must. I did sent the bolt off to the above mentioned company who very quickly identified it as BSF and sent me 6 new shiny ones which fit perfectly. I now have the bolts, new felt washers and new oil seals which once put back together should solve my tiller oil leak on my mk1 Clifford Rotavator!

[enginear]

Just to add when refitting bolt’s or nut’s use a small amount of copper grease on the thread’s this will enable them to be undone at a future date as long as the nut or bolt is not required to be thread locked,i have used copper grease for many year’s on agricultural machine’s even if it’s not me that would dismantle it again….

[Author]

Posts