Bolt thread type?

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  • January 25, 2018 at 2:40 pm #27749
    vhgmcbuddy
    Member

    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.

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    January 25, 2018 at 4:14 pm #27751
    charlie
    Keymaster

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

    January 25, 2018 at 5:24 pm #27752
    vhgmcbuddy
    Member

    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.

    January 25, 2018 at 7:49 pm #27754
    stuart
    Participant

    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 ??

    January 25, 2018 at 7:50 pm #27755
    vhgmcbuddy
    Member

    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!!

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    January 25, 2018 at 8:51 pm #27757
    hortiman
    Participant

    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

    January 25, 2018 at 10:43 pm #27758
    mickattwo
    Participant

    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

    January 26, 2018 at 12:27 am #27759
    wristpin
    Participant

    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

    January 26, 2018 at 10:10 am #27762
    charlie
    Keymaster

    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.

    January 26, 2018 at 4:02 pm #27764
    wristpin
    Participant

    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!

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    January 26, 2018 at 6:33 pm #27769
    vhgmcbuddy
    Member

    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.

    January 27, 2018 at 10:00 am #27770
    charlie
    Keymaster

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

    February 7, 2018 at 11:42 pm #27867
    vhgmcbuddy
    Member

    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

    February 7, 2018 at 11:48 pm #27868
    vhgmcbuddy
    Member

    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!

    February 9, 2018 at 1:05 pm #27873
    enginear
    Participant

    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….

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