Custom nut (Round slotted knurled thumb nut

[Philip LeeParticipant @philiplee66080]

Hi all,

I am an antique fan restorer but unfortunately I don't know how to make parts.

I am hoping that I can get some help from a hobbyist here that can help me to make a nut and please see the 2 photos.

Thanks.

https://drive.google.com/file/d/1vzl3h0_BJ1HRvjrDgkmBsajB2mZWrobK/view?usp=sharing

https://drive.google.com/file/d/1DPRbk_kCk7f_3ZgXQTBav8W_sU9yrNuf/view?usp=sharing

[Philip LeeParticipant @philiplee66080]

[bernard towersParticipant @bernardtowers37738]

If you post a drawing you may get a response

[Martin ConnellyParticipant @martinconnelly55370]

They don't look hard to make but a drawing showing material, dimensions and thread would be required to progress to manufacturing.

The other alternative is to pass the nut to someone who can use it as a prototype and copy it.

A rough guide to where you are would help with the second option.

Martin C

[DMRParticipant @dmr]

Looks like a custom part for the job/manufacturer. Probably bakelite which you would be very lucky to find. It would not have to be identical for anyone to notice but the thread needs to be the right one. BSF would be likely if its a UK make. As Martin says, you need to say where you are to help with that.

Dennis

[Philip LeeParticipant @philiplee66080]

I can definitely do a drawing with measurements. I am in Croydon, Surrey. Anyone near me?

[bernard towersParticipant @bernardtowers37738]

Does distance matter

[DC31kParticipant @dc31k]

Posted by DMR on 26/05/2023 16:18:10:

…Probably bakelite

What leads you to that conclusion?

In the photos the OP has posted, the part looks a little too metallic for that to be a possibility.

Edited By DC31k on 26/05/2023 17:17:53

[Philip LeeParticipant @philiplee66080]

Hi all,

Please see measurements and detailed photos. I don't know what material is it as I am not that technical.

https://drive.google.com/file/d/1HWhgbM66dfn1nRhUcrpl5fOoHYwAYyp8/view?usp=share_link

https://drive.google.com/file/d/1pe8bb13unBs3aesEdcIFLZhaUGj9U5LH/view?usp=share_link

https://drive.google.com/file/d/1s-qN_wmHo6hq8lsIerm8Uy9E04DLH3lr/view?usp=share_link

https://drive.google.com/file/d/159rueswZhKQq9lEbgkUlTKsn48xZZHxS/view?usp=share_link

Please let me know if anyone can help me out? I am happy to pay for your time/effort. I don't know the the thread measurement though. Perhaps it is something I can tackle myself?

Thanks in advanced.

[Howard LewisParticipant @howardlewis46836]

Even with dimensions, without knowing the thread (Size, and Form; Whitworth / BSF / BA/ Metric, etc) sadly, it will not be possible for anyone to help. You can't screw a BSF nut onto a BSW threads, for eaxample.

Howard

[Philip LeeParticipant @philiplee66080]

i understand about the thread size. As mentioned, can the nut be done so that I can tackle the thread myself? If not, I just have the buy a couple of imperial size nut and see which one fit and determine the size that way?

[Howard LewisParticipant @howardlewis46836]

This sounds like the dreaded "Can you just?"

To make the nut, the raw material will need to be faced, the OD turned to size, knurled, followed by drilling and tapping.,rbefore being eversed in the chuck to be fdaced .

You will need the correct Taps, (A set of three, ideallky. You will have great difficulty using just a bottoming Tap ) and a tapping size drill to cut your own thread.

Once you know what you have to produce..

Producing the thread as a second op, out of the lathe, risks producing it off axis and probably off centre. A job best done in the lathe while turning and knurling the OD.

Unless you are a good guesser, you may need several tries to get the correct nut to determine the thread

(And hardware suppliers are unlikely to be happy sell you just one nut. Some have a minimum order value ). Would you want to pay £6 for one nut only to find that it is the wrong one?

Better to determine what the thread is and to cut it while the job is still in the lathe.

What material do you want? And if steel, do you want it natural or blacked finish?

You need tohave the enswers to these questions before much can be done.

Howartd

[Philip LeeParticipant @philiplee66080]

i think i should be able to find out the thread size. Thanks for explaining these details to me as I have no knowledge of it. I think I will have to find out the thread size before progressing further here. Howard, are you able to do it for me if I have the thread size? Thanks.

Regarding the material, I am not fussed about it really and steel natural finish should be good.

Thanks.

[Philip LeeParticipant @philiplee66080]

I have the male side thread and is it possible to measure the male size thread or get a couple of imperial size nut to determine the right thread size? What tool can i buy to measure the thread size?

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Phillip, you need thread gauges to measure the thread you need, e. g. Arc Euro Trade

Get the Metric/Whitworth ones if it is British.

Regards Nick.

Edited By Nicholas Farr on 26/05/2023 19:03:32

[JasonBModerator @jasonb]

As you already have a nut you could work out the pitch by counting say 5 full turns of the nut and measuring how far along the male thread it moves. Then a measurement of the male thread's diameter and country of origin should get you looking in the right direction

[DC31kParticipant @dc31k]

Posted by Philip Lee on 26/05/2023 17:55:19:

If not, I just have the buy a couple of imperial size nut and see which one fit and determine the size that way?

Another possibility is to send the part the nut screws onto (the male thread) to the person making the nut. If they have the ability to make the nut, there is a high chance they will be able to ID the thread.

There is also some chance that the thread will be used elsewhere on the fan, so that might be another source of a male thread to send away for analysis.

[bernard towersParticipant @bernardtowers37738]

diameter looks a bit like 5/32 and tpi should be simple enough with a good rule and eye loupe

[Philip LeeParticipant @philiplee66080]

Thanks. 5/32 looks like BSW and 32 TPI, i can't see others.

BSW/BSF Thread Dimensions Chart

Am I nearly right?

[JasonBModerator @jasonb]

Do the turns of the nut test to confirm the tpi

What was the earlier measurement you put on the drawing the OD of the male or the clearance of the female hole in the nut?

What country does the fan originate from as that will be a good indicator of likely threads used

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Phillip, I agree with JasonB about the measurement that you have indicated on your nut drawing. A 5/32" thread will have a clearance hole in your nut of about 3.3mm, but not much more than 3.4mm. If the measurement you have shown is the O/D of the threaded stud, then 5/32" is probably correct.

Regards Nick.

[Philip LeeParticipant @philiplee66080]

The fan is build pre 1950 in Birmingham. Brand is Veritys. I am suspecting it is BSW as 5/32 is only for BSW and not BSF according to the chart table. 5/32 only do 32 tpi. Again, according to the chart.

BSW/BSF Thread Dimensions Chart

[JasonBModerator @jasonb]

BSC would also come in 5/32" x 32tpi

3BA is only a couple of thou larger as is M4 (unlikely)

#8-32 UNC is also just a couple of thou larger but possibly not now we know where it was made

[Bill PhinnParticipant @billphinn90025]

Philip, if I were you, I'd do the following:

Assuming it actually is 5/32" BSW, buy a good quality HSS 5/32" BSW tap set – currently possible for only £3.09. [I have this actual tap set and can vouch for its fitness for purpose].

Buy a suitable, near-enough equivalent, knurled thumb nut. N.B.: you want the one with the through hole, not the blind hole. I have bought quite a few of these in various sizes over the last few years.

The M3 one there is 11mm diameter, and any excess in the "m" measurement can be ground off the underside once you've finished the following procedures:

Slot the top of the nut to the required depth using a hacksaw.

Drill out the M3 tapped hole to 3.2mm.

Re-tap to 5/32" BSW.

Slightly dome the top of the nut by holding it by the underside in a hand drill and rotating against suitable abrasive material.

Use it.

Edited By Bill Phinn on 27/05/2023 13:29:19

[Philip LeeParticipant @philiplee66080]

Thanks Bill for the suggestion. How do i drill a 3.2mm hole and why is it 3.2? I supposed 3.2mm is the hole the 5/32 BSW tap set need ?

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